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 1-7 of 7 results.

A011801 Triangle read by rows, the inverse Bell transform of n!*binomial(4,n) (without column 0).

Original entry on oeis.org

1, 4, 1, 36, 12, 1, 504, 192, 24, 1, 9576, 3960, 600, 40, 1, 229824, 100656, 17160, 1440, 60, 1, 6664896, 3048192, 563976, 54600, 2940, 84, 1, 226606464, 107255232, 21095424, 2256576, 142800, 5376, 112, 1, 8837652096, 4302305280, 887785920, 102332160, 7254576, 325584, 9072, 144, 1
Offset: 1

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Keywords

Comments

Previous name was: Triangle of numbers related to triangle A049223; generalization of Stirling numbers of second kind A008277, Bessel triangle A001497.
T(n, m) = S2p(-4; n,m), a member of a sequence of triangles including S2p(-1; n,m) = A001497(n-1,m-1) (Bessel triangle) and ((-1)^(n-m))*S2p(1; n,m) = A008277(n,m) (Stirling 2nd kind). T(n, 1) = A008546(n-1).
For the definition of the Bell transform see A264428 and the link. - Peter Luschny, Jan 16 2016

Examples

			Triangle starts:
          1;
          4,         1;
         36,        12,        1;
        504,       192,       24,       1;
       9576,      3960,      600,      40,      1;
     229824,    100656,    17160,    1440,     60,     1;
    6664896,   3048192,   563976,   54600,   2940,    84,    1;
  226606464, 107255232, 21095424, 2256576, 142800,  5376,  112,   1;
		

Crossrefs

Cf. A028575 (row sums).
Triangles with the recurrence T(n,k) = (m*(n-1)-k)*T(n-1,k) + T(n-1,k-1): A010054 (m=1), A001497 (m=2), A004747 (m=3), A000369 (m=4), this sequence (m=5), A013988 (m=6).

Programs

  • Magma
    function T(n,k) // T = A011801
      if k eq 0 then return 0;
      elif k eq n then return 1;
      else return (5*(n-1)-k)*T(n-1,k) + T(n-1,k-1);
      end if;
    end function;
    [T(n,k): k in [1..n], n in [1..12]]; // G. C. Greubel, Oct 03 2023
  • Mathematica
    (* First program *)
    T[n_, m_] /; n>=m>=1:= T[n, m]= (5*(n-1)-m)*T[n-1, m] + T[n-1, m-1]; T[n_, m_] /; nJean-François Alcover, Jun 20 2018 *)
    (* Second program *)
    rows = 10;
    b[n_, m_]:= BellY[n, m, Table[k! Binomial[4, k], {k, 0, rows}]];
    T= Table[b[n, m], {n,rows}, {m,rows}]//Inverse//Abs;
    A011801= Table[T[[n, m]], {n,rows}, {m,n}]//Flatten (* Jean-François Alcover, Jun 22 2018 *)
  • Sage
    # uses[inverse_bell_matrix from A264428]
    # Adds 1,0,0,0, ... as column 0 at the left side of the triangle.
    inverse_bell_matrix(lambda n: factorial(n)*binomial(4, n), 8) # Peter Luschny, Jan 16 2016
    

Formula

T(n, m) = n!*A049223(n, m)/(m!*5^(n-m)).
T(n+1, m) = (5*n-m)*T(n, m) + T(n, m-1), for n >= m >= 1, with T(n, m) = 0, for n < m, and T(n, 0) = 0, T(1, 1) = 1.
E.g.f. of n-th column: (1/n!)*( 1 - (1-5*x)^(1/5) )^n.
Sum_{k=1..n} T(n, k) = A028575(n).

Extensions

New name from Peter Luschny, Jan 16 2016

A157404 A partition product of Stirling_2 type [parameter k = 4] with biggest-part statistic (triangle read by rows).

Original entry on oeis.org

1, 1, 4, 1, 12, 36, 1, 72, 144, 504, 1, 280, 1800, 2520, 9576, 1, 1740, 22320, 37800, 57456, 229824, 1, 8484, 182700, 864360, 1005480, 1608768, 6664896, 1, 57232, 2380896, 16546320, 26276544, 32175360, 53319168, 226606464
Offset: 1

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Author

Peter Luschny, Mar 09 2009

Keywords

Comments

Partition product of prod_{j=0..n-1}((k + 1)*j - 1) and n! at k = 4,
summed over parts with equal biggest part (see the Luschny link).
Underlying partition triangle is A144267.
Same partition product with length statistic is A011801.
Diagonal a(A000217) = A008546.
Row sum is A028575.

Crossrefs

Formula

T(n,0) = [n = 0] (Iverson notation) and for n > 0 and 1 <= m <= n
T(n,m) = Sum_{a} M(a)|f^a| where a = a_1,..,a_n such that
1*a_1+2*a_2+...+n*a_n = n and max{a_i} = m, M(a) = n!/(a_1!*..*a_n!),
f^a = (f_1/1!)^a_1*..*(f_n/n!)^a_n and f_n = product_{j=0..n-1}(5*j - 1).

A015735 Row sums of triangle A004747.

Original entry on oeis.org

1, 3, 17, 145, 1661, 23931, 415773, 8460257, 197360985, 5192853011, 152137882601, 4911873672113, 173268075672277, 6630323916472075, 273555262963272501, 12105084133976359361, 571897644855277242673, 28731255563712689630627, 1529450942687399074134465
Offset: 1

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Crossrefs

Programs

  • Magma
    R:=PowerSeriesRing(Rationals(), 30); Coefficients(R!(Laplace( Exp(1-(1-3*x)^(1/3)) - 1 ))); // G. C. Greubel, Oct 02 2023
    
  • Mathematica
    a[1]=1; a[n_]:= 1 +(n-1)!*Sum[Binomial[k, n-m-k]*Binomial[k+n-1,n-1]*(-1/3)^(n-m-k)/(m-1)!, {m,n}, {k,n-m}]; Table[a[n], {n,20}] (* Jean-François Alcover, Jul 05 2013, after Vladimir Kruchinin *)
    Rest@With[{m=30}, CoefficientList[Series[Exp[1-Surd[1-3*x,3]] -1, {x, 0,m}], x]*Range[0,m]!] (* G. C. Greubel, Oct 02 2023 *)
  • Maxima
    a(n):=if n=1 then 1 else (n-1)!*sum(sum(binomial(k,n-m-k)* (-1/3)^(n-m-k)*binomial(k+n-1,n-1),k,1,n-m)/(m-1)!,m,1,n)+1; /* Vladimir Kruchinin, Aug 08 2010 */
    
  • SageMath
    def A015735_list(prec):
        P. = PowerSeriesRing(QQ, prec)
        return P( exp(1-(1-3*x)^(1/3)) -1 ).egf_to_ogf().list()
    a=A015735_list(40); a[1:] # G. C. Greubel, Oct 02 2023

Formula

E.g.f.: exp(1-(1-3*x)^(1/3)) - 1, if one takes a(0)=0.
a(n) = 6*(n-2)*a(n-1) - (3*n-8)*(3*n-7)*a(n-2) + a(n-3), a(0)=1, a(1)=1, a(2)=3.
a(n) = 1 + (n-1)!*Sum_{m=1..n} ( Sum_{k=1..n-m} C(k, n-m-k)*C(k+n-1, n-1)*(-1/3)^(n-m-k) ) / (m-1)!, n > 1. - Vladimir Kruchinin, Aug 08 2010
a(n) = D^n(exp(x)) evaluated at x = 0, where D is the operator 1/(1-x)^2*d/dx. Cf. A001515, A016036 and A028575. - Peter Bala, Nov 25 2011
E.g.f. with offset 0: exp(1-(1-3*x)^(1/3))/(1-3*x)^(2/3). - Sergei N. Gladkovskii, Jul 07 2012.
a(n) ~ sqrt(2*Pi)*3^(n-1)*exp(1-n)*n^(n-5/6)/Gamma(2/3) * (1-sqrt(3)*Gamma(2/3)^2/(2*Pi*n^(1/3))). - Vaclav Kotesovec, Aug 10 2013
From Seiichi Manyama, Jan 20 2025: (Start)
a(n) = Sum_{k=0..n} (-1)^k * 3^(n-k) * |Stirling1(n,k)| * A000587(k).
a(n) = e * (-3)^n * n! * Sum_{k>=0} (-1)^k * binomial(k/3,n)/k!. (End)

A016036 Row sums of triangle A000369.

Original entry on oeis.org

1, 4, 31, 361, 5626, 109951, 2585269, 71066626, 2236441141, 79289379361, 3127129674736, 135802922499949, 6439320471558781, 331026965612789356, 18338413238239145731, 1089132347371148170381, 69033182553940825258594, 4651256393180943757676371
Offset: 1

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Crossrefs

Sequences with e.g.f. exp(1-(1-m*x)^(1/m)) - 1: A000012 (m=1), A001515 (m=2), A015735 (m=3), this sequence (m=4), A028575 (m=5), A028844 (m=6).
Cf. A000369.

Programs

  • Magma
    R:=PowerSeriesRing(Rationals(), 30); Coefficients(R!(Laplace( Exp(1-(1-4*x)^(1/4)) -1 ))); // G. C. Greubel, Oct 02 2023
    
  • Mathematica
    a[n_, m_] /; (n>= m>= 1):= a[n, m]= (4*(n-1)-m)*a[n-1,m] + a[n-1,m-1]; a[n_, m_] /; n,0]= 0; a[1,1] = 1; a[n]:= Sum[a[n,m], {m, n}]; Table[a[n], {n,20}] (* Jean-François Alcover, Feb 28 2013 *)
    With[{nn=20},CoefficientList[Series[Exp[1-Surd[1-4x,4]]-1,{x,0,nn}],x] Range[0,nn]!]//Rest (* Harvey P. Dale, Apr 20 2016 *)
  • Maxima
    a(n):=((n-1)!*sum((sum(binomial(n+k-1,n-1)*sum(binomial(j,n-m-3*k+2*j)*binomial(k,j)*3^(-n+m+3*k-j)*2^(n-m-5*k+3*j)*(-1)^(n-m-k),j,0,k),k,1,n-m))/(m-1)!,m,1,n-1))+1; /* Vladimir Kruchinin, Oct 18 2011 */
    
  • SageMath
    def A016036_list(prec):
        P. = PowerSeriesRing(QQ, prec)
        return P( exp(1-(1-4*x)^(1/4)) -1 ).egf_to_ogf().list()
    a=A016036_list(40); a[1:] # G. C. Greubel, Oct 02 2023

Formula

E.g.f.: exp(1 - (1-4*x)^(1/4)) - 1.
a(n) = 6*(2*n-5)*a(n-1) - 3*(16*n^2-96*n+145)*a(n-2) + 2*(4*n-15)*(2*n-7)*(4*n-13)*a(n-3) + a(n-4), n >= 4; a(0) = 1, a(1) = 1, a(2) = 4, a(3) = 31.
a(n) = 1 + (n-1)!*Sum_{m=1..n-1} ( Sum_{k=1..n-m} binomial(n+k-1,n-1) * ( Sum_{j=0..k} binomial(j,n-m-3*k+2*j)*binomial(k,j)*3^(-n+m+3*k-j)*2^(n-m-5*k+3*j)*(-1)^(n-m-k) ) )/(m-1)!. - Vladimir Kruchinin, Oct 18 2011
a(n) = D^n(exp(x)) evaluated at x = 0, where D is the operator 1/(1-x)^3*d/dx. Cf. A001515, A015735 and A028575. - Peter Bala, Nov 25 2011
a(n) ~ 2^(2*n-3/2)*n^(n-3/4)*exp(1-n)*sqrt(Pi)/Gamma(3/4) * (1 - Gamma(3/4)/(n^(1/4)*sqrt(Pi)) + Gamma(3/4)^2/(4*sqrt(n/2)*Pi)). - Vaclav Kotesovec, Aug 10 2013
From Seiichi Manyama, Jan 20 2025: (Start)
a(n) = Sum_{k=0..n} (-1)^k * 4^(n-k) * |Stirling1(n,k)| * A000587(k).
a(n) = e * (-4)^n * n! * Sum_{k>=0} (-1)^k * binomial(k/4,n)/k!. (End)

A028844 Row sums of triangle A013988.

Original entry on oeis.org

1, 6, 71, 1261, 29906, 887751, 31657851, 1318279586, 62783681421, 3365947782611, 200610405843926, 13157941480889921, 941848076798467801, 73060842413607398806, 6105266987293752470991, 546770299628690541571901, 52244284936267317229542466, 5305131708827069245129523591
Offset: 1

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Keywords

Crossrefs

Sequences with e.g.f. exp(1-(1-m*x)^(1/m)) - 1: A000012 (m=1), A001515 (m=2), A015735 (m=3), A016036 (m=4), A028575 (m=5), this sequence (m=6).

Programs

  • Magma
    R:=PowerSeriesRing(Rationals(), 30); Coefficients(R!(Laplace( Exp(1-(1-6*x)^(1/6)) -1 ))); // G. C. Greubel, Oct 03 2023
    
  • Mathematica
    With[{nn=20},Rest[CoefficientList[Series[Exp[1-(1-6x)^(1/6)]-1,{x,0,nn}], x]Range[0,nn]!]] (* Harvey P. Dale, Feb 02 2012 *)
  • SageMath
    def A028844_list(prec):
        P. = PowerSeriesRing(QQ, prec)
        return P( exp(1-(1-6*x)^(1/6)) -1 ).egf_to_ogf().list()
    a=A028844_list(40); a[1:] # G. C. Greubel, Oct 03 2023

Formula

E.g.f.: exp(1 - (1-6*x)^(1/6)) - 1.
D-finite with recurrence: a(n) = 15*(2*n-7)*a(n-1) +5*(72*n^2-576*n+1169)*a(n-2) +45*(2*n-9)*(24*n^2-216*n+497)*a(n-3) -20*(324*n^4-6480*n^3+48735*n^2-163350*n+205877)*a(n-4) +12*(6*n-35)*(6*n-31)*(3*n-16)*(2*n-11)*(3*n-17)*a(n-5) +a(n-6). - R. J. Mathar, Jan 28 2020
From Seiichi Manyama, Jan 20 2025: (Start)
a(n) = Sum_{k=0..n} (-1)^k * 6^(n-k) * |Stirling1(n,k)| * A000587(k).
a(n) = e * (-6)^n * n! * Sum_{k>=0} (-1)^k * binomial(k/6,n)/k!. (End)

A380310 Expansion of e.g.f. exp( 1 - 1/(1-5*x)^(1/5) ).

Original entry on oeis.org

1, -1, -5, -49, -719, -14077, -344909, -10152829, -349045535, -13727327833, -607873987637, -29931556660105, -1622308999459631, -95982568510668373, -6155361624644676989, -425321834949751148053, -31502433469012320013631, -2489898822489054343250737, -209178052238110675644666341
Offset: 0

Views

Author

Seiichi Manyama, Jan 20 2025

Keywords

Crossrefs

Programs

  • PARI
    my(N=20, x='x+O('x^N)); Vec(serlaplace(exp(1-1/(1-5*x)^(1/5))))

Formula

a(n) = Sum_{k=0..n} 5^(n-k) * |Stirling1(n,k)| * A000587(k).
a(n) = e * (-5)^n * n! * Sum_{k>=0} (-1)^k * binomial(-k/5,n)/k!.
a(0) = 1; a(n) = -Sum_{k=1..n} A008548(k) * binomial(n-1,k-1) * a(n-k).

A380307 Expansion of e.g.f. exp( (1+5*x)^(1/5) - 1 ).

Original entry on oeis.org

1, 1, -3, 25, -335, 6177, -144947, 4128937, -138327615, 5327738497, -231899041475, 11255588133945, -602683483719503, 35288931375293857, -2242963870471014963, 153791777744471484745, -11314787069889491407103, 889087243145447511507969, -74312052321224600661026051
Offset: 0

Views

Author

Seiichi Manyama, Jan 20 2025

Keywords

Crossrefs

Programs

  • PARI
    my(N=20, x='x+O('x^N)); Vec(serlaplace(exp((1+5*x)^(1/5)-1)))

Formula

a(n) = Sum_{k=0..n} 5^(n-k) * Stirling1(n,k) * Bell(k).
a(n) = (1/e) * 5^n * n! * Sum_{k>=0} binomial(k/5,n)/k!.
a(0) = 1; a(n) = Sum_{k=1..n} (Product_{j=0..k-1} (-5*j+1)) * binomial(n-1,k-1) * a(n-k).
Showing 1-7 of 7 results.