cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

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A111596 The matrix inverse of the unsigned Lah numbers A271703.

Original entry on oeis.org

1, 0, 1, 0, -2, 1, 0, 6, -6, 1, 0, -24, 36, -12, 1, 0, 120, -240, 120, -20, 1, 0, -720, 1800, -1200, 300, -30, 1, 0, 5040, -15120, 12600, -4200, 630, -42, 1, 0, -40320, 141120, -141120, 58800, -11760, 1176, -56, 1, 0, 362880, -1451520, 1693440, -846720, 211680, -28224, 2016, -72, 1
Offset: 0

Views

Author

Wolfdieter Lang, Aug 23 2005

Keywords

Comments

Also the associated Sheffer triangle to Sheffer triangle A111595.
Coefficients of Laguerre polynomials (-1)^n * n! * L(n,-1,x), which equals (-1)^n * Lag(n,x,-1) below. Lag(n,Lag(.,x,-1),-1) = x^n evaluated umbrally, i.e., with (Lag(.,x,-1))^k = Lag(k,x,-1). - Tom Copeland, Apr 26 2014
Without row n=0 and column m=0 this is, up to signs, the Lah triangle A008297.
The unsigned column sequences are (with leading zeros): A000142, A001286, A001754, A001755, A001777, A001778, A111597-A111600 for m=1..10.
The row polynomials p(n,x) := Sum_{m=0..n} a(n,m)*x^m, together with the row polynomials s(n,x) of A111595 satisfy the exponential (or binomial) convolution identity s(n,x+y) = Sum_{k=0..n} binomial(n,k)*s(k,x)*p(n-k,y), n>=0.
Exponential Riordan array [1,x/(1+x)]. Inverse of the exponential Riordan array [1,x/(1-x)], which is the unsigned version of A111596. - Paul Barry, Apr 12 2007
For the unsigned subtriangle without column number m=0 and row number n=0, see A105278.
Unsigned triangle also matrix product |S1|*S2 of Stirling number matrices.
The unsigned row polynomials are Lag(n,-x,-1), the associated Laguerre polynomials of order -1 with negated argument. See Gradshteyn and Ryzhik, Abramowitz and Stegun and Rota (Finite Operator Calculus) for extensive formulas. - Tom Copeland, Nov 17 2007, Sep 09 2008
An infinitesimal matrix generator for unsigned A111596 is given by A132792. - Tom Copeland, Nov 22 2007
From the formalism of A132792 and A133314 for n > k, unsigned A111596(n,k) = a(k) * a(k+1)...a(n-1) / (n-k)! = a generalized factorial, where a(n) = A002378(n) = n-th term of first subdiagonal of unsigned A111596. Hence Deutsch's remark in A002378 provides an interpretation of A111596(n,k) in terms of combinations of certain circular binary words. - Tom Copeland, Nov 22 2007
Given T(n,k)= A111596(n,k) and matrices A and B with A(n,k) = T(n,k)*a(n-k) and B(n,k) = T(n,k)*b(n-k), then A*B = C where C(n,k) = T(n,k)*[a(.)+b(.)]^(n-k), umbrally. - Tom Copeland, Aug 27 2008
Operationally, the unsigned row polynomials may be expressed as p_n(:xD:) = x*:Dx:^n*x^{-1}=x*D^nx^n*x^{-1}= n!*binomial(xD+n-1,n) = (-1)^n n! binomial(-xD,n) = n!L(n,-1,-:xD:), where, by definition, :AB:^n = A^nB^n for any two operators A and B, D = d/dx, and L(n,-1,x) is the Laguerre polynomial of order -1. A similarity transformation of the operators :Dx:^n generates the higher order Laguerre polynomials, which can also be expressed in terms of rising or falling factorials or Kummer's confluent hypergeometric functions (cf. the Mathoverflow post). - Tom Copeland, Sep 21 2019

Examples

			Binomial convolution of row polynomials: p(3,x) = 6*x-6*x^2+x^3; p(2,x) = -2*x+x^2, p(1,x) = x, p(0,x) = 1,
together with those from A111595: s(3,x) = 9*x-6*x^2+x^3; s(2,x) = 1-2*x+x^2, s(1,x) = x, s(0,x) = 1; therefore
9*(x+y)-6*(x+y)^2+(x+y)^3 = s(3,x+y) = 1*s(0,x)*p(3,y) + 3*s(1,x)*p(2,y) + 3*s(2,x)*p(1,y) +1*s(3,x)*p(0,y) = (6*y-6*y^2+y^3) + 3*x*(-2*y+y^2) + 3*(1-2*x+x^2)*y + 9*x-6*x^2+x^3.
From _Wolfdieter Lang_, Apr 28 2014: (Start)
The triangle a(n,m) begins:
n\m  0     1       2       3      4     5   6  7
0:   1
1:   0     1
2:   0    -2       1
3:   0     6      -6       1
4:   0   -24      36     -12      1
5:   0   120    -240     120    -20     1
6:   0  -720    1800   -1200    300   -30   1
7:   0  5040  -15120   12600  -4200   630 -42  1
...
For more rows see the link.
(End)
		

Crossrefs

Row sums: A111884. Unsigned row sums: A000262.
A002868 gives maximal element (in magnitude) in each row.
Cf. A130561 for a natural refinement.
Cf. A264428, A264429, A271703 (unsigned).
Cf. A008297, A089231, A105278 (variants).

Programs

  • Maple
    # The function BellMatrix is defined in A264428.
    BellMatrix(n -> `if`(n::odd, -(n+1)!, (n+1)!), 9); # Peter Luschny, Jan 27 2016
  • Mathematica
    a[0, 0] = 1; a[n_, m_] := ((-1)^(n-m))*(n!/m!)*Binomial[n-1, m-1]; Table[a[n, m], {n, 0, 10}, {m, 0, n}] // Flatten (* Jean-François Alcover, Jul 05 2013 *)
    T[ n_, k_] := (-1)^n n! Coefficient[ LaguerreL[ n, -1, x], x, k]; (* Michael Somos, Dec 15 2014 *)
    rows = 9;
    t = Table[(-1)^(n+1) n!, {n, 1, rows}];
    T[n_, k_] := BellY[n, k, t];
    Table[T[n, k], {n, 0, rows}, {k, 0, n}]  // Flatten (* Jean-François Alcover, Jun 22 2018, after Peter Luschny *)
  • PARI
    {T(n, k) = if( n<1 || k<1, n==0 && k==0, (-1)^n * n! * polcoeff( sum(k=1, n, binomial( n-1, k-1) * (-x)^k / k!), k))}; /* Michael Somos, Dec 15 2014 */
  • Sage
    lah_number = lambda n, k: factorial(n-k)*binomial(n,n-k)*binomial(n-1,n-k)
    A111596_row = lambda n: [(-1)^(n-k)*lah_number(n, k) for k in (0..n)]
    for n in range(10): print(A111596_row(n)) # Peter Luschny, Oct 05 2014
    
  • Sage
    # uses[inverse_bell_transform from A264429]
    def A111596_matrix(dim):
        fact = [factorial(n) for n in (1..dim)]
        return inverse_bell_transform(dim, fact)
    A111596_matrix(10) # Peter Luschny, Dec 20 2015
    

Formula

E.g.f. m-th column: ((x/(1+x))^m)/m!, m>=0.
E.g.f. for row polynomials p(n, x) is exp(x*y/(1+y)).
a(n, m) = ((-1)^(n-m))*|A008297(n, m)| = ((-1)^(n-m))*(n!/m!)*binomial(n-1, m-1), n>=m>=1; a(0, 0)=1; else 0.
a(n, m) = -(n-1+m)*a(n-1, m) + a(n-1, m-1), n>=m>=0, a(n, -1):=0, a(0, 0)=1; a(n, m)=0 if n
|a(n,m)| = Sum_{k=m..n} |S1(n,k)|*S2(k,m), n>=0. S2(n,m):=A048993. S1(n,m):=A048994. - Wolfdieter Lang, May 04 2007
From Tom Copeland, Nov 21 2011: (Start)
For this Lah triangle, the n-th row polynomial is given umbrally by
(-1)^n n! binomial(-Bell.(-x),n), where Bell_n(-x)= exp(x)(xd/dx)^n exp(-x), the n-th Bell / Touchard / exponential polynomial with neg. arg., (cf. A008277). E.g., 2! binomial(-Bell.(-x),2) = -Bell.(-x)*(-Bell.(-x)-1) = Bell_2(-x)+Bell_1(-x) = -2x+x^2.
A Dobinski relation is (-1)^n n! binomial(-Bell.(-x),n)= (-1)^n n! e^x Sum_{j>=0} (-1)^j binomial(-j,n)x^j/j!= n! e^x Sum_{j>=0} (-1)^j binomial(j-1+n,n)x^j/j!. See the Copeland link for the relation to inverse Mellin transform. (End)
The n-th row polynomial is (-1/x)^n e^x (x^2*D_x)^n e^(-x). - Tom Copeland, Oct 29 2012
Let f(.,x)^n = f(n,x) = x!/(x-n)!, the falling factorial,and r(.,x)^n = r(n,x) = (x-1+n)!/(x-1)!, the rising factorial, then the Lah polynomials, Lah(n,t)= n!*Sum{k=1..n} binomial(n-1,k-1)(-t)^k/k! (extra sign factor on odd rows), give the transform Lah(n,-f(.,x))= r(n,x), and Lah(n,r(.,x))= (-1)^n * f(n,x). - Tom Copeland, Oct 04 2014
|T(n,k)| = Sum_{j=0..2*(n-k)} A254881(n-k,j)*k^j/(n-k)!. Note that A254883 is constructed analogously from A254882. - Peter Luschny, Feb 10 2015
The T(n,k) are the inverse Bell transform of [1!,2!,3!,...] and |T(n,k)| are the Bell transform of [1!,2!,3!,...]. See A264428 for the definition of the Bell transform and A264429 for the definition of the inverse Bell transform. - Peter Luschny, Dec 20 2015
Dividing each n-th diagonal by n!, where the main diagonal is n=1, generates a shifted, signed Narayana matrix A001263. - Tom Copeland, Sep 23 2020

Extensions

New name using a comment from Wolfdieter Lang by Peter Luschny, May 10 2021

A002868 Largest number in n-th row of triangle of Lah numbers (A008297 and A271703).

Original entry on oeis.org

1, 1, 2, 6, 36, 240, 1800, 15120, 141120, 1693440, 21772800, 299376000, 4390848000, 68497228800, 1133317785600, 19833061248000, 396661224960000, 8299373322240000, 181400588328960000, 4135933413900288000, 98228418580131840000, 2426819753156198400000
Offset: 0

Keywords

References

  • N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
  • N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Crossrefs

Essentially the same as A001286.

Programs

  • Haskell
    a002868 n = if n == 0 then 1 else maximum $ map abs $ a008297_row n
    -- Reinhard Zumkeller, Sep 30 2014
  • Maple
    with(combinat): for n from 0 to 35 do big := 1: for m from 1 to n do if big < n!*binomial(n-1,m-1)/m! then big := n!*binomial(n-1,m-1)/m! fi: od: printf(`%d,`,big): od:
  • Mathematica
    a[n_] := ( big = 1; For[ m = 1 , m <= n, m++, b = n!*Binomial[n - 1, m - 1]/m!; If[ big < b , big = b ]]; big); Table[a[n], {n, 0, 19}] (* Jean-François Alcover, Sep 21 2012, after Maple *)

Formula

For 2 <= n <= 7, equals (n+1)!*n/2. - Alexander R. Povolotsky, Oct 16 2006

Extensions

More terms from James Sellers, Jan 03 2001

A059110 Triangle T = A007318*A271703; T(n,m)= Sum_{i=0..n} L'(n,i)*binomial(i,m), m=0..n.

Original entry on oeis.org

1, 1, 1, 3, 4, 1, 13, 21, 9, 1, 73, 136, 78, 16, 1, 501, 1045, 730, 210, 25, 1, 4051, 9276, 7515, 2720, 465, 36, 1, 37633, 93289, 85071, 36575, 8015, 903, 49, 1, 394353, 1047376, 1053724, 519456, 137270, 20048, 1596, 64, 1, 4596553, 12975561
Offset: 0

Author

Vladeta Jovovic, Jan 04 2001

Keywords

Comments

L'(n,i) are unsigned Lah numbers (cf. A008297): L'(n,i)=n!/i!*binomial(n-1,i-1) for i >= 1, L'(0,0)=1, L'(n,0)=0 for n>0. T(n,0)=A000262(n); T(n,2)=A052852(n). Row sums A052897.
Exponential Riordan array [e^(x/(1-x)),x/(1-x)]. - Paul Barry, Apr 28 2007
From Wolfdieter Lang, Jun 22 2017: (Start)
The inverse matrix T^(-1) is exponential Riordan (aka Sheffer) (e^(-x), x/(1+x)): T^(-1)(n, m) = (-1)^(n-m)*A271705(n, m).
The a- and z-sequences of this Sheffer (aka exponential Riordan) matrix are a = [1,1,repeat(0)] and z(n) = (-1)^(n+1)*A028310(n)/A000027(n-1) with e.g.f. ((1+x)/x)*(1-exp(-x)). For a- and z-sequences see a W. Lang link under A006232 with references. (End)

Examples

			The triangle T = A007318*A271703 starts:
n\m       0        1        2       3       4      5     6    7  8 9 ...
0:        1
1:        1        1
2:        3        4        1
3:       13       21        9       1
4:       73      136       78      16       1
5:      501     1045      730     210      25      1
6:     4051     9276     7515    2720     465     36     1
7:    37633    93289    85071   36575    8015    903    49    1
8:   394353  1047376  1053724  519456  137270  20048  1596   64  1
9:  4596553 12975561 14196708 7836276 2404206 427518 44436 2628 81 1
... reformatted. - _Wolfdieter Lang_, Jun 22 2017
E.g.f. for T(n, 2) = 1/2!*(x/(1-x))^2*e^(x/(x-1)) = 1*x^2/2 + 9*x^3/3! + 78*x^4/4! + 730*x^5/5! + 7515*x^6/6 + ...
From _Wolfdieter Lang_, Jun 22 2017: (Start)
The z-sequence starts: [1, 1/2, -2/3, 3/4, -4/5, 5/6, -6/7, 7/8, -8/9, ...
T recurrence: T(3, 0) = 3*(1*T(2,0) + (1/2)*T(2, 1) + (-2/3)*T(2 ,1)) = 3*(3 + (1/2)*4 - (2/3)) = 13; T(3, 1) = 3*(T(2, 0)/1 + T(2, 1)) = 3*(3 + 4) = 21.
Meixner type recurrence for R(2, x): (D - D^2)*(3 + 4*x + x^2) = 4 + 2*x - 2 = 2*(1 + x), (D = d/dx).
General Sheffer recurrence for R(2, x): (1+x)*(1 + 2*D + D^2)*(1 + x) = (1+x)*(1 + x + 2) = 3 + 4*x + x^2. (End)
		

Programs

  • GAP
    Concatenation([1],Flat(List([1..10],n->List([0..n],m->Sum([0..n],i-> Factorial(n)/Factorial(i)*Binomial(n-1,i-1)*Binomial(i,m)))))); # Muniru A Asiru, Jul 25 2018
    
  • Magma
    A059110:= func< n,k | n eq 0 select 1 else Factorial(n-1)*Binomial(n,k)*Evaluate(LaguerrePolynomial(n-1, 1-k), -1) >;
    [A059110(n,k): k in [0..n], n in [0..12]]; // G. C. Greubel, Feb 23 2021
  • Maple
    Lprime := proc(n,i)
        if n = 0 and i = 0 then
            1;
        elif k = 0 then
            0 ;
        else
            n!/i!*binomial(n-1,i-1) ;
        end if;
    end proc:
    A059110 := proc(n,k)
        add(Lprime(n,i)*binomial(i,k),i=0..n) ;
    end proc: # R. J. Mathar, Mar 15 2013
  • Mathematica
    (* First program *)
    lp[n_, i_] := Binomial[n-1, i-1]*n!/i!; lp[0, 0] = 1; t[n_, m_] := Sum[lp[n, i]*Binomial[i, m], {i, 0, n}]; Table[t[n, m], {n, 0, 9}, {m, 0, n}] // Flatten (* Jean-François Alcover, Mar 26 2013 *)
    (* Second program *)
    A059110[n_, k_]:= If[n==0, 1, (n-1)!*Binomial[n, k]*LaguerreL[n-1, 1-k, -1]];
    Table[A059110[n, k], {n,0,12}, {k,0,n}]//Flatten (* G. C. Greubel, Feb 23 2021 *)
  • Sage
    def A059110(n, k): return 1 if n==0 else factorial(n-1)*binomial(n, k)*gen_laguerre(n-1, 1-k, -1)
    flatten([[A059110(n,k) for k in (0..n)] for n in (0..12)]) # G. C. Greubel, Feb 23 2021
    

Formula

E.g.f. for column m: (1/m!)*(x/(1-x))^m*e^(x/(x-1)), m >= 0.
From Wolfdieter Lang, Jun 22 2017: (Start)
E.g.f. for row polynomials in powers of x (e.g.f. of the triangle): exp(z/(1-z))* exp(x*z/(1-z)) (exponential Riordan).
Recurrence: T(n, 0) = Sum_{j=0} z(j)*T(n-1, j), n >= 1, with z(n) = (-1)^(n+1)*A028310(n), T(0, 0) = 1, T(n, m) = 0 n < m, T(n, m) = n*(T(n-1, m-1)/m + T(n-1, m)), n >= m >= 1 (from the z- and a-sequence, see a comment above).
Meixner type recurrence for the (monic) row polynomials R(n, x) = Sum_{m=0..n} T(n, m)*x^m: Sum_{k=0..n-1} (-1)^k*D^(k+1)*R(n, x) = n*R(n-1, x), n >=1, R(0, x) = 1, with D = d/dx.
General Sheffer recurrence: R(n, x) = (x+1)*(1+D)^2*R(n-1, x), n >=1, R(0, x) = 1.
(End)
P_n(x) = L_n(1+x) = n!*Lag_n(-(1+x);1), where P_n(x) are the row polynomials of this entry; L_n(x), the Lah polynomials of A105278; and Lag_n(x;1), the Laguerre polynomials of order 1. These relations follow from the relation between the iterated operator (x^2 D)^n and ((1+x)^2 D)^n with D = d/dx. - Tom Copeland, Jul 18 2018
From G. C. Greubel, Feb 23 2021: (Start)
T(n, k) = (n-1)!*binomial(n, k)*LaguerreL(n-1, 1-k, -1) with T(0, 0) = 1.
Sum_{k=0..n} T(n, k) = A052897(n). (End)

A271705 Triangle read by rows, T(n,k) = Sum_{j=0..n} C(n,j)*L(j,k), L the unsigned Lah numbers A271703, for n>=0 and 0<=k<=n.

Original entry on oeis.org

1, 1, 1, 1, 4, 1, 1, 15, 9, 1, 1, 64, 66, 16, 1, 1, 325, 490, 190, 25, 1, 1, 1956, 3915, 2120, 435, 36, 1, 1, 13699, 34251, 23975, 6755, 861, 49, 1, 1, 109600, 328804, 283136, 101990, 17696, 1540, 64, 1, 1, 986409, 3452436, 3534636, 1554966, 342846, 40404, 2556, 81, 1
Offset: 0

Author

Peter Luschny, Apr 14 2016

Keywords

Comments

This is the Sheffer (aka exponential Riordan) matrix T = P*L = A007318*A271703 = (exp(x), x/(1-x)). Note that P = A007318 is Sheffer (exp(t), t) (of the Appell type). The Sheffer a-sequence is [1,1,repeat(0)] and the z-sequence has e.g.f. (x/(1+x))*(1 - exp(-x/(1+x)) given in A288869 / A000027. Because the column k=0 has only entries 1, the z-sequence gives fractional representations of 1. See A288869. - Wolfdieter Lang, Jun 20 2017

Examples

			Triangle starts:
  1;
  1,    1;
  1,    4,    1;
  1,   15,    9,    1;
  1,   64,   66,   16,   1;
  1,  325,  490,  190,  25,  1;
  1, 1956, 3915, 2120, 435, 36, 1;
  ...
Recurrence: T(3, 2) = (3/2)*4 + 3*1 = 9. - _Wolfdieter Lang_, Jun 20 2017
		

Crossrefs

Cf. A000290 (diag n, n-1), A062392 (diag n, n-2).
Cf. A007526 (col. 1), A134432 (col. 2).
Cf. A052844 (row sums), A059110 (matrix inverse).

Programs

  • Magma
    B:=Binomial;
    A271705:= func< n,k | k eq 0 select 1 else (&+[B(n, j+k)*B(j+k, k)*B(j+k-1, k-1)*Factorial(j): j in [0..n-k]]) >;
    [A271705(n,k): k in [0..n], n in [0..12]]; // G. C. Greubel, Jan 09 2022
    
  • Maple
    L := (n,k) -> `if`(k<0 or k>n,0,(n-k)!*binomial(n,n-k)*binomial(n-1,n-k)):
    T := (n,k) -> add(L(j,k)*binomial(-j-1,-n-1)*(-1)^(n-j), j=0..n):
    seq(seq(T(n,k), k=0..n), n=0..9);
  • Mathematica
    T[n_, k_]:= If[k==0, 1, Sum[((k*j!)/(j+k))*Binomial[n, j+k]*Binomial[j+k, k]^2, {j,0,n-k}]];
    Table[T[n, k], {n,0,12}, {k,0,n}]//Flatten (* G. C. Greubel, Jan 09 2022 *)
  • Sage
    b=binomial
    def A271705(n,k): return 1 if (k==0) else sum(factorial(j-k)*b(n, j)*b(j, k)*b(j-1, k-1) for j in (k..n))
    flatten([[A271705(n,k) for k in (0..n)] for n in (0..12)]) # G. C. Greubel, Jan 09 2022

Formula

From Wolfdieter Lang, Jun 20 2017: (Start)
T(n, k) = Sum_{m=k..n} A007318(n, m)*A271703(m, k), n >= k >= 0, and 0 for k < m. See also the name.
E.g.f. of column k: exp(x)*(x/(1-x))^k/k! (Sheffer property), k >= 0.
E.g.f. of triangle (or row polynomials in x): exp(z)*exp(x*z/(1-z)).
Recurrence for T(n, k), k >= 1, with T(n, 0) = 1, T(n, k) = 0 if n < k: T(n, k) = (n/k)*T(n-1, k-1) + n*T(n-1, k), n >= 1, k = 1..n. (From the a-sequence with column k=0 as input.) (End)
T(n, k) = Sum_{j=0..n-k} j!*binomial(n, j+k)*binomial(j+k, k)*binomial(j+k-1, k-1) with T(n, 0) = 1. - G. C. Greubel, Jan 09 2022
From Natalia L. Skirrow, Jun 11 2025: (Start)
T(n, k) = C(n, k)*hypergeom([k-n, k], [], -1), which equals C(n, k)*A143409(n-k, k-1) for k>0.
By the saddle point method upon the e.g.f., n-th row polynomial converges with n (for all y) to n^n*exp(2*sqrt(n*y) - n - y/2 + 1)/sqrt(2*sqrt(n/y)); as such, the n-th row's expectation is ~ sqrt(n)-1/4 and the n-th row's variance is ~ (sqrt(n)-1)/2. (End)

A288869 Numerators of z-sequence for the Sheffer matrix T = P*Lah = A271703 = A007318*A271703 = (exp(t), t/(1-t)).

Original entry on oeis.org

1, -1, 4, -21, 136, -1045, 9276, -93289, 1047376, -12975561, 175721140, -2581284541, 40864292184, -693347907421, 12548540320876, -241253367679185, 4909234733857696, -105394372192969489, 2380337795595885156
Offset: 0

Author

Wolfdieter Lang, Jun 20 2017

Keywords

Comments

The denominators seem to be the natural numbers A000027.
The z-sequence gives the recurrence for column k=0 entries of the triangle T = A271703 (using also lower rows of T): T(n, 0) = Sum_{j=0..n-1} z(j)*T(n-1, j), n >=1, with T(0, 0) = 1. Because column k=0 has e.g.f. exp(x) all entries T(n, 0) = 1, and one obtains rational representations of 1 by the z-sequence recurrence. See the examples.

Examples

			The rationals r(n) begin: 1, -1/2, 4/3, -21/4, 136/5, -1045/6, 9276/7, -93289/8, 1047376/9, -12975561/10, 175721140/11, -2581284541/12, 40864292184/13, -693347907421/14, 12548540320876/15, ...
Recurrence with T= P*Lah = A271703, rational representations of 1:
  1 = T(2, 0) = 2*(1*T(1, 0) + (-1/2)*T(1, 1)) = 2*(1 - 1/2) = 1.
  1 = T(3, 0) = 3*(1*1 + (-1/2)*4 + (4/3)*1) = 1.
  1 = T(4, 0) = 4*(1*1 + (-1/2)*15 + (4/3)*9 + (-21/4)*1) = 1.
  ...
		

Crossrefs

Programs

  • Magma
    [1] cat [(-1)^n*Factorial(n+1)*Evaluate(LaguerrePolynomial(n+1, -2), -1): n in [1..30]]; // G. C. Greubel, Jan 09 2022
    
  • Mathematica
    Table[If[n==0, 1, (-1)^n*(n+1)!*LaguerreL[n+1, -2, -1]], {n, 0, 30}] (* G. C. Greubel, Jan 09 2022 *)
  • PARI
    a(n) = if (n, (-1)^n*(n+1)!*subst(pollaguerre(n+1, -2), x, -1), 1); \\ Michel Marcus, Jan 09 2022
  • Sage
    [1]+[(-1)^n*factorial(n+1)*gen_laguerre(n+1, -2, -1) for n in (1..30)] # G. C. Greubel, Jan 09 2022
    

Formula

E.g.f. for the rationals r(n): ((1+x)/x)*(1 - exp(-x/(1+x))).
a(n) = numerator(r(n)) (in lowest terms).
From G. C. Greubel, Jan 09 2022: (Start)
a(n) = (-1)^n * (n+1)! * Laguerre(n+1, -2, -1), with a(0) = 1.
a(n) = (-1)^n * (n+1)! * Sum_{j=0..n-1} binomial(n-1, j)/(j+2)!, with a(0) = 1. (End)

A344050 a(n) = Sum_{k=0..n} (-1)^(n-k)*binomial(n, k)*|Lah(n, k)|. Inverse binomial convolution of the unsigned Lah numbers A271703.

Original entry on oeis.org

1, 1, -3, 1, 73, -699, 3001, 24697, -783999, 10946233, -80958779, -656003919, 40097528857, -944102982419, 14449693290033, -81180376526759, -4110744092532479, 203618771909117937, -5868277577182238579, 117997016943575159713, -1055340561026036009559, -45279878749358024400299
Offset: 0

Author

Peter Luschny, May 10 2021

Keywords

Crossrefs

Programs

  • Maple
    aList := proc(len) local lah;
    lah := (n, k) -> `if`(n = k, 1, binomial(n-1, k-1)*n!/k!):
    seq(add((-1)^(n-k)*binomial(n, k)*lah(n, k), k = 0..n), n = 0..len-1) end:
    print( aList(22) );
  • Mathematica
    a[n_] := (-1)^(n-1) n n! HypergeometricPFQ[{1 - n, 1 - n}, {2, 2}, -1]; a[0] := 1;
    Table[a[n], {n, 0, 20}]

Formula

a(n) = (-1)^(n-1)*n*n!*hypergeom([1 - n, 1 - n], [2, 2], -1) for n >= 1.

A355004 a(n) = Sum_{k=0..n} A271703(k + n, n), row sums of A355005.

Original entry on oeis.org

1, 3, 43, 1333, 63321, 4034341, 321994723, 30869387193, 3454384526353, 441903886812721, 63608031487665171, 10174227287873082853, 1790258521269694523113, 343669522619597368671933, 71473405251333054552561091, 16008271911444915765782477041, 3841639137772270982094393928353
Offset: 0

Author

Peter Luschny, Jun 15 2022

Keywords

Crossrefs

Cf. A271703 (unsigned Lah), A355005, A187535.

Programs

  • Maple
    L := (n, k) -> ifelse(n = k, 1, binomial(n-1, k-1)*n! / k!):
    seq(add(L(n + k, n), k = 0..n), n = 0..16);
  • Mathematica
    Table[Sum[Binomial[n + k, n]*FactorialPower[n + k - 1, k], {k, 0, n}], {n, 0, 20}] (* Vaclav Kotesovec, Jun 15 2022 *)

Formula

a(n) = A187535(n) * hypergeom([1, -n], [1 - 2*n, -2*n], -1).
From Vaclav Kotesovec, Jun 15 2022: (Start)
Recurrence: (n-1)^2 * n * (64*n^4 - 464*n^3 + 1244*n^2 - 1475*n + 663)*a(n) = (n-1)*(2*n-3)*(512*n^6 - 3968*n^5 + 11872*n^4 - 17336*n^3 + 12880*n^2 - 4597*n + 617)*a(n-1) + (2048*n^7 - 19968*n^6 + 78912*n^5 - 163216*n^4 + 191140*n^3 - 128857*n^2 + 48842*n - 8937)*a(n-2) + 4*(2*n-5)*(2*n-3)*(64*n^4 - 208*n^3 + 236*n^2 - 123*n + 32)*a(n-3).
a(n) ~ 2^(4*n - 1/2) * n^(n - 1/2) / (sqrt(Pi) * exp(n)). (End)

A372348 a(n) = Sum_{j=0..n} p(n - j, j) where p(n, x) = Sum_{k=0..n} k! * Lah(n, k) * x^k where Lah = A271703.

Original entry on oeis.org

1, 1, 2, 7, 40, 329, 3550, 47755, 777812, 15048925, 341018314, 8946278015, 268923178720, 9176058440977, 352386991982390, 15115253160180019, 719367763801641580, 37767206102310829445, 2176271214087106315042, 137024328250953628940455, 9388717924596833591237624
Offset: 0

Author

Peter Luschny, Apr 28 2024

Keywords

Crossrefs

Cf. A271703.

Programs

  • Maple
    Lah := (n, k) -> ifelse(n = k, 1, binomial(n-1, k-1)*n!/k!):
    p := n -> local k; add(k!*Lah(n, k)*x^k, k = 0..n):
    a := n -> local j; add(subs(x=j, p(n - j)), j = 0..n):
    seq((a(n)), n = 0..21);

A271704 Triangle read by rows, T(n,k) = Sum_{j=0..n} (-1)^(n-j)*C(-j,-n)*L(j,k), L the unsigned Lah numbers A271703, for n>=0 and 0<=k<=n.

Original entry on oeis.org

1, 0, 1, 0, 3, 1, 0, 11, 8, 1, 0, 49, 57, 15, 1, 0, 261, 424, 174, 24, 1, 0, 1631, 3425, 1930, 410, 35, 1, 0, 11743, 30336, 21855, 6320, 825, 48, 1, 0, 95901, 294553, 259161, 95235, 16835, 1491, 63, 1, 0, 876809, 3123632, 3251500, 1452976, 325150, 38864, 2492, 80, 1
Offset: 0

Author

Peter Luschny, Apr 14 2016

Keywords

Examples

			Triangle starts:
  [1]
  [0, 1]
  [0, 3,     1]
  [0, 11,    8,     1]
  [0, 49,    57,    15,    1]
  [0, 261,   424,   174,   24,   1]
  [0, 1631,  3425,  1930,  410,  35,  1]
  [0, 11743, 30336, 21855, 6320, 825, 48, 1]
		

Crossrefs

A001339 (col. 1), A005563 (diag. n,n-1).

Programs

  • Maple
    L := (n,k) -> `if`(k<0 or k>n,0,(n-k)!*binomial(n,n-k)*binomial(n-1,n-k)):
    T := (n,k) -> add(L(j,k)*binomial(-j,-n)*(-1)^(n-j), j=0..n):
    seq(seq(T(n,k), k=0..n), n=0..9);

Formula

From Natalia L. Skirrow, Jun 12 2025: (Start)
Definition can also be written Sum_{j=0..n} C(n-1, j-1)*L(j, k), where C(n, -1) = (1 if n = -1 else 0) over integer n.
T(n, k) = C(n-1, k-1)*A143409(n-k, k) = k*(k+1)*A271705(n+1, k+1)/(n*(n+1)) for n > 0.
E.g.f. for sequence b(n, k) = T(n+1, k+1): F/(1-x)^2, where F = exp(x + y*x/(1-x)) is e.g.f. of A271705.
E.g.f. for kth column of b: exp(x)*x^(k-1)/(1-x)^(k+1)/(k-1)!. (These cannot be integrated with x to give e.g.f.s for T(n, k) using standard functions.)
T(n, k) = Sum_{i=0..n-k} (n-1)_i*(i+1)*A271705(n-1-i, k-1), where (n)_i = n!/(n-i)! is the falling factorial. (End)

A271706 Triangle read by rows: T(n, k) = Sum_{j=0..n} C(-j-1, -n-1)*L(j, k), L the unsigned Lah numbers A271703, for n >= 0 and 0 <= k <= n.

Original entry on oeis.org

1, -1, 1, 1, 0, 1, -1, 3, 3, 1, 1, 8, 18, 8, 1, -1, 45, 110, 70, 15, 1, 1, 264, 795, 640, 195, 24, 1, -1, 1855, 6489, 6335, 2485, 441, 35, 1, 1, 14832, 59332, 67984, 32550, 7504, 868, 48, 1, -1, 133497, 600732, 789852, 445914, 126126, 19068, 1548, 63, 1
Offset: 0

Author

Peter Luschny, Apr 20 2016

Keywords

Examples

			Triangle starts:
  [ 1]
  [-1,    1]
  [ 1,    0,    1]
  [-1,    3,    3,    1]
  [ 1,    8,   18,    8,    1]
  [-1,   45,  110,   70,   15,   1]
  [ 1,  264,  795,  640,  195,  24,  1]
  [-1, 1855, 6489, 6335, 2485, 441, 35, 1]
		

Crossrefs

A052845 (row sums), A000240 (col. 1), A000274 (col. 2), A067998 (diag n,n-1).

Programs

  • Maple
    L := (n, k) -> `if`(k<0 or k>n, 0, (n-k)!*binomial(n, n-k)*binomial(n-1, n-k)):
    T := (n, k) -> add(L(j, k)*binomial(-j-1,-n-1), j=0..n):
    seq(seq(T(n, k), k=0..n), n=0..9);
    # Or:
    T := (n, k) -> (-1)^(n-k)*binomial(n, k)*hypergeom([k-n, k], [], 1):
    for n from 0 to 8 do seq(simplify(T(n, k)), k=0..n) od; # Peter Luschny, Jun 25 2025

Formula

T(n, k) = (-1)^(k-n)*binomial(n, k)*hypergeom([k-n, k], [], 1). (After a formula of Natalia L. Skirrow in A271705.) - Peter Luschny, Jun 25 2025
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