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 1-5 of 5 results.

A336195 a(0) = 1; a(n) = Sum_{k=0..n-1} binomial(n,k)^3 * a(k).

Original entry on oeis.org

1, 1, 9, 271, 19353, 2699251, 650553183, 248978967973, 142238892608025, 115699539306013867, 129097362200437841259, 191726066802105786953113, 369666963359241578736653775, 906204961889202975320635813201, 2774573804997927027583123365125685
Offset: 0

Views

Author

Ilya Gutkovskiy, Jul 11 2020

Keywords

Crossrefs

Column k=3 of A326322.

Programs

  • Mathematica
    a[0] = 1; a[n_] := a[n] = Sum[Binomial[n, k]^3 a[k], {k, 0, n - 1}]; Table[a[n], {n, 0, 14}]
    nmax = 14; CoefficientList[Series[1/(1 - Sum[x^k/(k!)^3, {k, 1, nmax}]), {x, 0, nmax}], x] Range[0, nmax]!^3

Formula

a(n) = (n!)^3 * [x^n] 1 / (1 - Sum_{k>=1} x^k / (k!)^3).

A212858 Number of 5 X n arrays with rows being permutations of 0..n-1 and no column j greater than column j-1 in all rows.

Original entry on oeis.org

1, 1, 31, 7291, 7225951, 21855093751, 164481310134301, 2675558106868421881, 84853928323286139485791, 4849446032811641059203617551, 469353176282647626764795665676281, 73159514984813223626195834388445570381, 17619138865526260905773841471696025142373661
Offset: 0

Views

Author

R. H. Hardin, May 28 2012

Keywords

Comments

From Petros Hadjicostas, Sep 08 2019: (Start)
We generalize Daniel Suteu's recurrence from A212856. Notice first that, in the notation of Abramson and Promislow (1978), we have a(n) = R(m=5, n, t=0).
Letting y=0 in Eq. (8), p. 249, of Abramson and Promislow (1978), we get 1 + Sum_{n >= 1} R(m,n,t=0)*x^n/(n!)^m = 1/f(-x), where f(x) = Sum_{i >= 0} (x^i/(i!)^m). Matching coefficients, we get Sum_{s = 1..n} R(m, s, t=0) * (-1)^(s-1) * binomial(n,s)^m = 1, from which the recurrence in the Formula section follows.
(End)

Examples

			Some solutions for n=3:
  2 0 1   0 1 2   0 2 1   0 2 1   1 2 0   0 2 1   2 0 1
  2 0 1   2 1 0   0 1 2   0 2 1   0 1 2   1 2 0   2 0 1
  0 1 2   2 0 1   0 2 1   2 1 0   0 1 2   0 1 2   2 1 0
  2 0 1   0 1 2   1 2 0   0 2 1   1 0 2   2 1 0   1 0 2
  1 2 0   0 2 1   2 1 0   1 2 0   0 1 2   2 1 0   2 1 0
		

Crossrefs

Programs

  • Maple
    A212858 := proc(n) sum(z^k/k!^5, k = 0..infinity);
    series(%^x, z=0, n+1): n!^5*coeff(%,z,n); add(abs(coeff(%,x,k)), k=0..n) end:
    seq(A212858(n), n=1..12); # Peter Luschny, May 27 2017
  • Mathematica
    T[n_, k_] := T[n, k] = If[k == 0, 1, -Sum[Binomial[k, j]^n*(-1)^j*T[n, k - j], {j, 1, k}]];
    a[n_] := T[5, n];
    Table[a[n], {n, 0, 12}] (* Jean-François Alcover, Apr 01 2024, after Alois P. Heinz in A212855 *)

Formula

a(n) = (-1)^(n-1) + Sum_{s = 1..n-1} a(s) * (-1)^(n-s-1) * binomial(n,s)^m for n >= 2 with a(1) = 1. Here m = 5. - Petros Hadjicostas, Sep 08 2019
a(n) = (n!)^5 * [x^n] 1 / (1 + Sum_{k>=1} (-x)^k / (k!)^5). (see Petros Hadjicostas's comment on Sep 08 2019) - Seiichi Manyama, Jul 18 2020

Extensions

a(0)=1 prepended by Seiichi Manyama, Jul 18 2020

A336196 a(0) = 1; a(n) = Sum_{k=0..n-1} binomial(n,k)^4 * a(k).

Original entry on oeis.org

1, 1, 17, 1459, 395793, 262131251, 359993423843, 915919888063853, 3975467425523532305, 27639424688447366285203, 292886774320942590679779267, 4544030770812055230064359134573, 99847457331663057820508375752459491, 3021907600842518917755426740899056448141
Offset: 0

Views

Author

Ilya Gutkovskiy, Jul 11 2020

Keywords

Crossrefs

Column k=4 of A326322.

Programs

  • Mathematica
    a[0] = 1; a[n_] := a[n] = Sum[Binomial[n, k]^4 a[k], {k, 0, n - 1}]; Table[a[n], {n, 0, 13}]
    nmax = 13; CoefficientList[Series[1/(1 - Sum[x^k/(k!)^4, {k, 1, nmax}]), {x, 0, nmax}], x] Range[0, nmax]!^4

Formula

a(n) = (n!)^4 * [x^n] 1 / (1 - Sum_{k>=1} x^k / (k!)^4).

A336261 a(0) = 1; a(n) = (n!)^5 * Sum_{k=0..n-1} a(k) / (k! * (n-k))^5.

Original entry on oeis.org

1, 1, 33, 8294, 8790208, 28436662624, 228929520628448, 3983602580423420352, 135150778123405293748224, 8262821715336263175482769408, 855516444430388524429593124012032, 142657102263368111456587968163250896896, 36753801552552818015956675623665562408714240
Offset: 0

Views

Author

Ilya Gutkovskiy, Jul 15 2020

Keywords

Crossrefs

Programs

  • Maple
    b:= proc(n) option remember; `if`(n=0, 1,
          add(b(n-i)/i^5, i=1..n))
        end:
    a:= n-> n!^5*b(n):
    seq(a(n), n=0..14);  # Alois P. Heinz, Jan 04 2024
  • Mathematica
    a[0] = 1; a[n_] := a[n] = (n!)^5 Sum[a[k]/(k! (n - k))^5, {k, 0, n - 1}]; Table[a[n], {n, 0, 12}]
    nmax = 12; CoefficientList[Series[1/(1 - PolyLog[5, x]), {x, 0, nmax}], x] Range[0, nmax]!^5

Formula

a(n) = (n!)^5 * [x^n] 1 / (1 - polylog(5,x)).
a(n) ~ (n!)^5 / (polylog(4,r) * r^n), where r = 0.96581751668950729310276791428... is the root of the equation polylog(5,r) = 1. - Vaclav Kotesovec, Jul 15 2020

A342199 a(0) = 1; a(n) = Sum_{k=1..n} binomial(n,k)^5 * a(k-1).

Original entry on oeis.org

1, 1, 33, 519, 43111, 5068111, 840782023, 291086377719, 139698959369111, 90748115988081551, 90809507057803456103, 124011515918275951611959, 217278911997171247450862041, 509237348184229328050319432621, 1567286639251140454692258569881053
Offset: 0

Views

Author

Ilya Gutkovskiy, Mar 04 2021

Keywords

Crossrefs

Programs

  • Mathematica
    a[0] = 1; a[n_] := a[n] = Sum[Binomial[n, k]^5 a[k - 1], {k, 1, n}]; Table[a[n], {n, 0, 14}]
Showing 1-5 of 5 results.