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.

A211210 a(n) = Sum_{k=0..n} binomial(n, k)*|S1(n, k)|.

Original entry on oeis.org

1, 1, 3, 16, 115, 1021, 10696, 128472, 1734447, 25937683, 424852351, 7554471156, 144767131444, 2971727661124, 65013102375404, 1509186299410896, 37032678328740751, 957376811266995031, 25999194631060525009, 739741591417352081464, 22000132609456951524051
Offset: 0

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Author

Olivier Gérard, Oct 23 2012

Keywords

Comments

Binomial convolution of the unsigned Stirling numbers of the first kind.
Row sums of triangle A187555.

Crossrefs

Cf. A317274 (signed S1), A187555, A134090, A211211.
Cf. A122455 (second kind), A271702, A134094, A343841 (second kind inverse).

Programs

  • Mathematica
    Table[Sum[Binomial[n, k] Abs[StirlingS1[n, k]], {k, 0, n}], {n, 0, 20}]
  • PARI
    a(n) = sum(k=0, n, binomial(n, k)*abs(stirling(n, k, 1))); \\ Michel Marcus, May 10 2021

A176153 Triangle T(n,k) = Sum_{j=0..k} Stirling1(n, n-j)*binomial(n,j), read by rows.

Original entry on oeis.org

1, 1, 1, 1, -1, -1, 1, -8, -2, -2, 1, -23, 43, 19, 19, 1, -49, 301, -199, -79, -79, 1, -89, 1186, -3314, 796, 76, 76, 1, -146, 3529, -22196, 34644, -2400, 2640, 2640, 1, -223, 8793, -100967, 372863, -362529, 3375, -36945, -36945, 1, -323, 19333, -361691, 2466883, -6010901, 3911515, -33509, 329371, 329371
Offset: 0

Views

Author

Roger L. Bagula, Apr 10 2010

Keywords

Examples

			Triangle begins as:
  1;
  1,    1;
  1,   -1,   -1;
  1,   -8,   -2,      -2;
  1,  -23,   43,      19,     19;
  1,  -49,  301,    -199,    -79,     -79;
  1,  -89, 1186,   -3314,    796,      76,   76;
  1, -146, 3529,  -22196,  34644,   -2400, 2640,   2640;
  1, -223, 8793, -100967, 372863, -362529, 3375, -36945, -36945;
		

Crossrefs

Programs

  • GAP
    Flat(List([0..10], n-> List([0..n], k-> Sum([0..k], j-> (-1)^j*Stirling1(n,n-j)* Binomial(n,j)) ))); # G. C. Greubel, Nov 26 2019
  • Magma
    [(&+[StirlingFirst(n, n-j)*Binomial(n,j): j in [0..k]]): k in [0..n], n in [0..10]]; // G. C. Greubel, Nov 26 2019
    
  • Maple
    seq(seq( add(combinat[stirling1](n,n-j)*binomial(n,j), j=0..k), k=0..n), n=0..10); # G. C. Greubel, Nov 26 2019
  • Mathematica
    T[n_, k_]:= Sum[StirlingS1[n, n-j]*Binomial[n, j], {j,0,k}];
    Table[T[n, k], {n,0,10}, {k,0,n}]//Flatten
  • PARI
    T(n,k) = sum(j=0,k, stirling(n,n-j,1)*binomial(n,j)); \\ G. C. Greubel, Nov 26 2019
    
  • Sage
    [[sum((-1)^j*stirling_number1(n, n-j)*binomial(n,j) for j in (0..k)) for k in (0..n)] for n in (0..10)] # G. C. Greubel, Nov 26 2019
    

Formula

T(n, k) = Sum_{j=0..k} Stirling1(n, n-j)*binomial(n, j).
T(n, n) = A317274(n). - G. C. Greubel, Aug 03 2021

A047798 a(n) = Sum_{k=0..n} C(n,k)*Stirling2(n,k)^2.

Original entry on oeis.org

1, 1, 3, 31, 443, 9006, 241147, 7956579, 318973867, 15061651528, 824029357046, 51526959899570, 3636995712432667, 287053182699020609, 25126145438688593769, 2421761360666327615911, 255466264644678162575691, 29336098320197429601856772
Offset: 0

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Author

Keywords

Crossrefs

Programs

  • GAP
    List([0..20], n-> Sum([0..n], k-> Binomial(n,k)*Stirling2(n,k)^2 )); # G. C. Greubel, Aug 07 2019
  • Magma
    [(&+[Binomial(n,k)*StirlingSecond(n,k)^2: k in [0..n]]): n in [0..20]]; // G. C. Greubel, Aug 07 2019
    
  • Maple
    seq(add(binomial(n,k)*stirling2(n, k)^2, k = 0..n), n = 0..20); # G. C. Greubel, Aug 07 2019
  • Mathematica
    Table[Sum[Binomial[n, k]*StirlingS2[n, k]^2, {k,0,n}], {n,0,20}] (* G. C. Greubel, Aug 07 2019 *)
  • PARI
    {a(n) = sum(k=0,n, binomial(n,k)*stirling(n,k,2)^2)};
    vector(20, n, n--; a(n)) \\ G. C. Greubel, Aug 07 2019
    
  • Sage
    [sum(binomial(n,k)*stirling_number2(n,k)^2 for k in (0..n)) for n in (0..20)] # G. C. Greubel, Aug 07 2019
    

A343841 a(n) = Sum{k=0..n} (-1)^(n-k)*binomial(n, k)*Stirling2(n, k).

Original entry on oeis.org

1, 1, -1, -5, 15, 56, -455, -237, 16947, -64220, -529494, 6833608, -8606015, -459331677, 4335744673, 6800310151, -518075832085, 4315086396640, 19931595013738, -812870258798156, 6648395876520816, 46852711038750520, -1752440325584024944, 15485712825845269456
Offset: 0

Views

Author

Peter Luschny, May 04 2021

Keywords

Crossrefs

Programs

  • Maple
    a := n -> add((-1)^(n-k)*binomial(n, k)*Stirling2(n, k), k=0..n):
    seq(a(n), n = 0..24);
  • Mathematica
    a[n_] := Sum[(-1)^(n - k) * Binomial[n, k] * StirlingS2[n, k], {k, 0, n}]; Array[a, 24, 0] (* Amiram Eldar, May 07 2021 *)
  • PARI
    a(n) = sum(k=0, n, (-1)^(n-k)*binomial(n, k)*stirling(n, k, 2)); \\ Michel Marcus, May 07 2021

A308565 a(n) = Sum_{k=0..n} binomial(n,k) * Stirling1(n,k) * k!.

Original entry on oeis.org

1, 1, 0, -6, -12, 140, 1020, -5208, -117264, -2448, 17756640, 117905040, -3177424800, -56997933408, 523176632160, 25824592321920, 31907065317120, -12118922683971840, -151839867298498560, 5619086944920958464, 172859973799199892480, -1989399401447725854720, -170925579909303883614720
Offset: 0

Views

Author

Ilya Gutkovskiy, Jun 07 2019

Keywords

Crossrefs

Programs

  • Mathematica
    Table[Sum[Binomial[n, k] StirlingS1[n, k] k!, {k, 0, n}], {n, 0, 22}]
    Table[n! SeriesCoefficient[(1 + Log[1 + x])^n, {x, 0, n}], {n, 0, 22}]

Formula

a(n) = n! * [x^n] (1 + log(1 + x))^n.

A344053 a(n) = Sum_{k=0..n} (-1)^(n-k)*binomial(n, k)*Stirling2(n, k)*k!.

Original entry on oeis.org

1, 1, 0, -9, -40, 125, 3444, 18571, -241872, -5796711, -24387220, 1132278191, 25132445832, 8850583573, -10681029498972, -214099676807085, 1643397436986464, 176719161389104817, 2976468247699317468, -71662294521163070153, -4638920054290748840520, -55645074852328083377619
Offset: 0

Views

Author

Peter Luschny, May 10 2021

Keywords

Comments

Inverse binomial convolution of the Fubini numbers (A131689).

Crossrefs

Programs

  • Mathematica
    a[n_] := Sum[(-1)^(n - k) * Binomial[n, k] * StirlingS2[n, k] * k!, {k, 0, n}]; Array[a, 22, 0] (* Amiram Eldar, May 10 2021 *)
  • PARI
    a(n) = sum(k=0, n, (-1)^(n-k)*binomial(n, k)*stirling(n, k, 2)*k!); \\ Michel Marcus, May 10 2021

Formula

a(n) = Sum_{k=0..n} (-1)^k * A219859(n,k). - Alois P. Heinz, Jan 24 2022
a(n) = n! * [x^n] (2 - exp(-x))^n. - Fabian Pereyra, Aug 31 2024
Showing 1-6 of 6 results.