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.

Showing 1-6 of 6 results.

A005727 n-th derivative of x^x at x=1. Also called Lehmer-Comtet numbers.

Original entry on oeis.org

1, 1, 2, 3, 8, 10, 54, -42, 944, -5112, 47160, -419760, 4297512, -47607144, 575023344, -7500202920, 105180931200, -1578296510400, 25238664189504, -428528786243904, 7700297625889920, -146004847062359040, 2913398154375730560, -61031188196889482880
Offset: 0

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Author

Keywords

References

  • L. Comtet, Advanced Combinatorics, Reidel, 1974, p. 139, table at foot of page.
  • G. H. Hardy, A Course of Pure Mathematics, 10th ed., Cambridge University Press, 1960, p. 428.
  • N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Crossrefs

Row sums of A008296. Column k=2 of A215703 and of A277537.

Programs

  • Maple
    A005727 := proc(n) option remember; `if`(n=0, 1, A005727(n-1)+add((-1)^(n-k)*(n-2-k)!*binomial(n-1, k)*A005727(k), k=0..n-2)) end:
    seq(A005727(n), n=0..23); # Mélika Tebni, May 22 2022
  • Mathematica
    NestList[ Factor[ D[ #1, x ] ]&, x^x, n ] /. (x->1)
    Range[0, 22]! CoefficientList[ Series[(1 + x)^(1 + x), {x, 0, 22}], x] (* Robert G. Wilson v, Feb 03 2013 *)
  • PARI
    a(n)=if(n<0,0,n!*polcoeff((1+x+x*O(x^n))^(1+x),n))

Formula

For n>0, a(n) = Sum_{k=0..n} b(n, k), where b(n, k) is a Lehmer-Comtet number of the first kind (see A008296).
E.g.f.: (1+x)^(1+x). a(n) = Sum_{k=0..n} Stirling1(n, k)*A000248(k). - Vladeta Jovovic, Oct 02 2003
From Mélika Tebni, May 22 2022: (Start)
a(0) = 1, a(n) = a(n-1)+Sum_{k=0..n-2} (-1)^(n-k)*(n-2-k)!*binomial(n-1, k)*a(k).
a(n) = Sum_{k=0..n} (-1)^(n-k)*A293297(k)*binomial(n, k).
a(n) = Sum_{k=0..n} (-1)^k*A203852(k)*binomial(n, k). (End)

A008296 Triangle of Lehmer-Comtet numbers of the first kind.

Original entry on oeis.org

1, 1, 1, -1, 3, 1, 2, -1, 6, 1, -6, 0, 5, 10, 1, 24, 4, -15, 25, 15, 1, -120, -28, 49, -35, 70, 21, 1, 720, 188, -196, 49, 0, 154, 28, 1, -5040, -1368, 944, 0, -231, 252, 294, 36, 1, 40320, 11016, -5340, -820, 1365, -987, 1050, 510, 45, 1, -362880, -98208, 34716, 9020, -7645, 3003, -1617, 2970, 825, 55, 1, 3628800
Offset: 1

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Author

Keywords

Comments

Triangle arising in the expansion of ((1+x)*log(1+x))^n.
Also the Bell transform of (-1)^(n-1)*(n-1)! if n>1 else 1 adding 1,0,0,0,... as column 0. For the definition of the Bell transform see A264428. - Peter Luschny, Jan 16 2016

Examples

			Triangle begins:
   1;
   1,  1;
  -1,  3,   1;
   2, -1,   6,  1;
  -6,  0,   5, 10,  1;
  24,  4, -15, 25, 15, 1;
  ...
		

References

  • L. Comtet, Advanced Combinatorics, Reidel, 1974, p. 139.

Crossrefs

Cf. A039621 (second kind), A354795 (variant), A185164, A005727 (row sums), A298511 (central).
Columns: A045406 (column 2), A347276 (column 3), A345651 (column 4).
Diagonals: A000142, A000217, A059302.
Cf. A176118.

Programs

  • Maple
    for n from 1 to 20 do for k from 1 to n do
    printf(`%d,`, add(binomial(l,k)*k^(l-k)*Stirling1(n,l), l=k..n)) od: od:
    # second program:
    A008296 := proc(n, k) option remember; if k=1 and n>1 then (-1)^n*(n-2)! elif n=k then 1 else (n-1)*procname(n-2, k-1) + (k-n+1)*procname(n-1, k) + procname(n-1, k-1) end if end proc:
    seq(print(seq(A008296(n, k), k=1..n)), n=1..7); # Mélika Tebni, Aug 22 2021
  • Mathematica
    a[1, 1] = a[2, 1] = 1; a[n_, 1] = (-1)^n (n-2)!;
    a[n_, n_] = 1; a[n_, k_] := a[n, k] = (n-1) a[n-2, k-1] + a[n-1, k-1] + (k-n+1) a[n-1,k]; Flatten[Table[a[n, k], {n, 1, 12}, {k, 1, n}]][[1 ;; 67]]
    (* Jean-François Alcover, Apr 29 2011 *)
  • PARI
    {T(n, k) = if( k<1 || k>n, 0, n! * polcoeff(((1 + x) * log(1 + x + x * O(x^n)))^k / k!, n))}; /* Michael Somos, Nov 15 2002 */
    
  • Sage
    # uses[bell_matrix from A264428]
    # Adds 1, 0, 0, 0, ... as column 0 at the left side of the triangle.
    bell_matrix(lambda n: (-1)^(n-1)*factorial(n-1) if n>1 else 1, 7) # Peter Luschny, Jan 16 2016

Formula

E.g.f. for a(n, k): (1/k!)[ (1+x)*log(1+x) ]^k. - Len Smiley
Left edge is (-1)*n!, for n >= 2. Right edge is all 1's.
a(n+1, k) = n*a(n-1, k-1) + a(n, k-1) + (k-n)*a(n, k).
a(n, k) = Sum_{m} binomial(m, k)*k^(m-k)*Stirling1(n, m).
From Peter Bala, Mar 14 2012: (Start)
E.g.f.: exp(t*(1 + x)*log(1 + x)) = Sum_{n>=0} R(n,t)*x^n/n! = 1 + t*x + (t+t^2)x^2/2! + (-t+3*t^2+t^3)x^3/3! + .... Cf. A185164. The row polynomials R(n,t) are of binomial type and satisfy the recurrence R(n+1,t) = (t-n)*R(n,t) + t*d/dt(R(n,t)) + n*t*R(n-1,t) with R(0,t) = 1 and R(1,t) = t. Inverse array is A039621.
(End)
Sum_{k=0..n} (-1)^k * a(n,k) = A176118(n). - Alois P. Heinz, Aug 25 2021

Extensions

More terms from James Sellers, Jan 26 2001
Edited by N. J. A. Sloane at the suggestion of Andrew Robbins, Dec 11 2007

A354795 Triangle read by rows. The matrix inverse of A354794. Equivalently, the Bell transform of cfact(n) = -(n - 1)! if n > 0 and otherwise 1/(-n)!.

Original entry on oeis.org

1, 0, 1, 0, -1, 1, 0, -1, -3, 1, 0, -2, -1, -6, 1, 0, -6, 0, 5, -10, 1, 0, -24, 4, 15, 25, -15, 1, 0, -120, 28, 49, 35, 70, -21, 1, 0, -720, 188, 196, 49, 0, 154, -28, 1, 0, -5040, 1368, 944, 0, -231, -252, 294, -36, 1, 0, -40320, 11016, 5340, -820, -1365, -987, -1050, 510, -45, 1
Offset: 0

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Author

Peter Luschny, Jun 09 2022

Keywords

Comments

The triangle is the matrix inverse of the Bell transform of n^n (A354794).
The numbers (-1)^(n-k)*T(n, k) are known as the Lehmer-Comtet numbers of 1st kind (A008296).
The function cfact is the 'complementary factorial' (name is ad hoc) and written \hat{!} in TeX mathmode. 1/(cfact(-n) * cfact(n)) = signum(-n) * n for n != 0. It is related to the Roman factorial (A159333). The Bell transform of the factorial are the Stirling cycle numbers (A132393).

Examples

			Triangle T(n, k) begins:
[0] [1]
[1] [0,     1]
[2] [0,    -1,    1]
[3] [0,    -1,   -3,   1]
[4] [0,    -2,   -1,  -6,   1]
[5] [0,    -6,    0,   5, -10,    1]
[6] [0,   -24,    4,  15,  25,  -15,    1]
[7] [0,  -120,   28,  49,  35,   70,  -21,   1]
[8] [0,  -720,  188, 196,  49,    0,  154, -28,   1]
[9] [0, -5040, 1368, 944,   0, -231, -252, 294, -36, 1]
		

References

  • Louis Comtet, Advanced Combinatorics. Reidel, Dordrecht, 1974, p. 139-140.

Crossrefs

Cf. A354794 (matrix inverse), A176118 (row sums), A005727 (alternating row sums), A045406 (column 2), A347276 (column 3), A345651 (column 4), A298511 (central), A008296 (variant), A159333, A264428, A159075, A006963, A354796.

Programs

  • Maple
    # The function BellMatrix is defined in A264428.
    cfact := n -> ifelse(n = 0, 1, -(n - 1)!): BellMatrix(cfact, 10);
    # Alternative:
    t := proc(n, k) option remember; if k < 0 or n < 0 then 0 elif k = n then 1 else (n-1)*t(n-2, k-1) - (n-1-k)*t(n-1, k) + t(n-1, k-1) fi end:
    T := (n, k) -> (-1)^(n-k)*t(n, k):
    seq(print(seq(T(n, k), k = 0..n)), n = 0..9);
    # Using the e.g.f.:
    egf := (1 - x)^(t*(x - 1)):
    ser := series(egf, x, 11): coeffx := n -> coeff(ser, x, n):
    row := n -> seq(n!*coeff(coeffx(n), t, k), k=0..n):
    seq(print(row(n)), n = 0..9);
  • Mathematica
    cfact[n_] := If[n == 0, 1, -(n - 1)!];
    R := Range[0, 10]; cf := Table[cfact[n], {n, R}];
    Table[BellY[n, k, cf], {n, R}, {k, 0, n}] // Flatten

Formula

T(n, k) = n!*[t^k][x^n] (1 - x)^(t*(x - 1)).
T(n, k) = Sum_{j=k..n} (-1)^(n-k)*binomial(j, k)*k^(j-k)*Stirling1(n, j).
T(n, k) = Bell_{n, k}(a), where Bell_{n, k} is the partial Bell polynomial evaluated over the sequence a = {cfact(m) | m >= 0}, (see Mathematica).
T(n, k) = (-1)^(n-k)*t(n, k) where t(n, n) = 1 and t(n, k) = (n-1)*t(n-2, k-1) - (n-1-k)*t(n-1, k) + t(n-1, k-1) for k > 0 and n > 0.
Let s(n) = (-1)^n*Sum_{k=1..n} (k-1)^(k-1)*T(n, k) for n >= 0, then s = A159075.
Sum_{k=1..n} (k + x)^(k-1)*T(n, k) = binomial(n + x - 1, n-1)*(n-1)! for n >= 1. Note that for x = k this is A354796(n, k) for 0 <= k <= n and implies in particular for x = n >= 1 the identity Sum_{k=1..n} (k + n)^(k - 1)*T(n, k) = Gamma(2*n)/n! = A006963(n+1).
E.g.f. of column k >= 0: ((1 - t) * log(1 - t))^k / ((-1)^k * k!). - Werner Schulte, Jun 14 2022

A211205 n-th derivative of x^(x^(x^(x^(x^x)))) at x=1.

Original entry on oeis.org

1, 1, 2, 9, 56, 480, 5094, 60494, 823528, 12365424, 206078880, 3745686912, 74083090872, 1579529362944, 36165466533000, 884104045301640, 22992315801392064, 633547543117707648, 18439576158792912192, 565162707747635408448, 18194047307015185486080
Offset: 0

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Author

Keywords

Crossrefs

Programs

  • Maple
    a:= n-> n!*coeff(series(subs(x=x+1, x^(x^(x^(x^(x^x))))), x, n+1), x, n):
    seq(a(n), n=0..20);
  • Mathematica
    NestList[ Factor[ D[#1, x]] &, x^x^x^x^x^x, 9] /. (x -> 1) (* or quicker *)
    Range[0, 20]! CoefficientList[ Series[(1 + x)^(1 + x)^(1 + x)^(1 + x)^(1 + x)^(1 + x), {x, 0, 20}], x]

Formula

E.g.f.: (x+1)^((x+1)^((x+1)^((x+1)^((x+1)^(x+1))))).

A350759 a(n) = Sum_{k=0..n} (-1)^k*A345652(k)*Stirling1(n, k).

Original entry on oeis.org

1, 0, -1, 1, 1, -4, 1, 29, -167, 1000, -7989, 75857, -794639, 9058180, -111944923, 1492748581, -21369667087, 326932765840, -5323818187817, 91947960224097, -1678914212753599, 32317295442288844, -654084630476955479, 13886774070229667213
Offset: 0

Views

Author

Mélika Tebni, Jan 14 2022

Keywords

Comments

Conjectures: For all p prime, (a(p) + a(p+1) - 2) == 0 (mod p),
a(p+1) == 1 (mod ((p+1)*p)).

Examples

			a(9) = -Sum_{k=0..7} a(k)*A238363(8, k).
a(9) = -(1*(-5040) + 0*(5760) - 1*(-3360) + 1*(1344) + 1*(-420) - 4*(112) + 1*(-28) + 29*(8)) = 1000.
E.g.f.: 1 - x^2/2! + x^3/3! + x^4/4! - 4*x^5/5! + x^6/6! + 29*x^7/7! - 167*x^8/8! + 1000*x^9/9! + ...
		

Crossrefs

Programs

  • Maple
    b := proc(n) option remember; `if`(n=0, 1, add((n-1)*binomial(n-2, k)*(-1)^(n-1-k)*b(k), k=0..n-2)) end:
    a := n-> add((-1)^k*b(k)*Stirling1(n, k), k=0..n):
    seq(a(n), n=0..23);
    # Second program:
    a := proc(n) option remember; `if`(n=0, 1, add((n-2-k)!*binomial(n-1, k)*(-1)^(n-1-k)*a(k), k=0..n-2)) end:
    seq(a(n), n=0..23);
    # Third program:
    a := series(exp(-1+(1+x)*(1-log(1+x))), x=0, 24):
    seq(n!*coeff(a, x, n), n=0..23);
    # Fourth program:
    A350759 := n-> add(binomial(n, k)*(n-k)!*coeftayl(x^(-x), x=1, n-k), k=0..n):
    seq(A350759 (n), n=0..23); # Mélika Tebni, Mar 31 2022
  • Mathematica
    CoefficientList[Series[Exp[-1+(1+x)*(1-Log[1+x])], {x, 0, 23}], x] * Range[0, 23]!
  • PARI
    my(x='x+O('x^30)); Vec(serlaplace(exp(-1 + (1 + x)*(1 - log(1 + x))))) \\ Michel Marcus, Jan 14 2022
  • Python
    from math import comb, factorial
    def a(n):
        return 1 if n == 0 else sum([factorial(n-2-k)*comb(n-1, k)*(-1)**(n-1-k)*a(k) for k in range(n-1)])
    print([a(n) for n in range(24)])
    

Formula

a(0) = 1, a(n) = -Sum_{k=0..n-2} a(k)*A238363(n-1, k) for n > 0.
a(0) = 1, a(n) = Sum_{k=0..n-2} (n-2-k)!*binomial(n-1, k)*(-1)^(n-1-k)*a(k) for n > 0.
E.g.f.: exp(-1 + (1 + x)*(1 - log(1 + x))).
E.g.f. y(x) satisfies y' + y*log(1 + x) = 0.
a(n) = Sum_{k=0..n} binomial(n, k)*A176118(n-k). - Mélika Tebni, Mar 31 2022
a(n) ~ -(-1)^n * n! * exp(-1) / n^2 * (1 - 2*log(n)/n). - Vaclav Kotesovec, Mar 31 2022

A366228 Expansion of e.g.f. A(x) satisfying A(x) = 1 + Integral A(x)^A(x) dx.

Original entry on oeis.org

1, 1, 1, 3, 12, 68, 473, 3998, 39327, 443599, 5629807, 79486044, 1235018598, 20946691457, 385025599130, 7624623236381, 161823815625933, 3664505951884255, 88189911547566082, 2247691180645108608, 60480432646998315279, 1713328345952593367876, 50970518521542636421145
Offset: 0

Views

Author

Paul D. Hanna, Nov 13 2023

Keywords

Comments

(a(n)/(n-1)!)^(1/n) tends to 1.42011... - Vaclav Kotesovec, Nov 15 2023

Examples

			E.g.f.: A(x) = 1 + x + x^2/2! + 3*x^3/3! + 12*x^4/4! + 68*x^5/5! + 473*x^6/6! + 3998*x^7/7! + 39327*x^8/8! + 443599*x^9/9! + 5629807*x^10/10! + ...
where A(x) = 1 + Integral A(x)^A(x) dx.
RELATED SERIES.
A(x)^A(x) = 1 + x + 3*x^2/2! + 12*x^3/3! + 68*x^4/4! + 473*x^5/5! + 3998*x^6/6! + 39327*x^7/7! + 443599*x^8/8! + ...
log(A(x)) = x + 2*x^3/3! + 3*x^4/4! + 32*x^5/5! + 155*x^6/6! + 1575*x^7/7! + 13573*x^8/8! + 160756*x^9/9! + 1938288*x^10/10! + ...
A(x)^(A(x) - 1) = 1 + 2*x^2/2! + 3*x^3/3! + 32*x^4/4! + 155*x^5/5! + 1575*x^6/6! + 13573*x^7/7! + ...
		

Crossrefs

Programs

  • PARI
    {a(n) = my(A=1); for(i=0, n, A = 1 + intformal( A^A +x*O(x^n) ) ); n!*polcoeff(A, n)}
    for(n=0, 30, print1(a(n), ", "))
    
  • PARI
    {a(n) = my(A=1); for(i=0, n, A = exp( intformal( A^(A-1) +x*O(x^n) ) ) ); n!*polcoeff(A, n)}
    for(n=0, 30, print1(a(n), ", "))

Formula

E.g.f. A(x) = Sum_{n>=0} a(n)*x^n/n! satisfies the following formulas.
(1) A(x) = 1 + Integral A(x)^A(x) dx.
(2) A(x) = exp( Integral A(x)^(A(x) - 1) dx ).
(3) A(x) = 1 + Series_Reversion( Integral 1/(1+x)^(1+x) dx ), where 1/(1+x)^(1+x) is the e.g.f. of A176118.
(4) A(x)^A(x) = 1/Sum_{n>=0} (1 - A(x))^n/n! * Product_{k=1..n} (k + A(x)-1) = A'(x). - Paul D. Hanna, Jul 25 2025
Showing 1-6 of 6 results.