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 1-3 of 3 results.

A351707 G.f. A(x) satisfies: A(x) = 1 + x + x^2 + x^3 + x^4 * A(x/(1 - x)) / (1 - x)^2.

Original entry on oeis.org

1, 1, 1, 1, 1, 3, 7, 15, 31, 65, 147, 373, 1051, 3157, 9761, 30573, 96965, 313999, 1049719, 3654303, 13284783, 50268837, 196638987, 789611161, 3238765671, 13540348965, 57710600953, 251163156089, 1118308871001, 5100825621147, 23838465463447, 114044805729151
Offset: 0

Views

Author

Ilya Gutkovskiy, Feb 16 2022

Keywords

Crossrefs

Programs

  • Mathematica
    nmax = 31; A[] = 0; Do[A[x] = 1 + x + x^2 + x^3 + x^4 A[x/(1 - x)]/(1 - x)^2 + O[x]^(nmax + 1) // Normal, nmax + 1]; CoefficientList[A[x], x]
    a[n_] := a[n] = If[n < 4, 1, Sum[Binomial[n - 3, k + 1] a[k], {k, 0, n - 4}]]; Table[a[n], {n, 0, 31}]

Formula

a(0) = ... = a(3) = 1; a(n) = Sum_{k=0..n-4} binomial(n-3,k+1) * a(k).

A351754 G.f. A(x) satisfies: A(x) = 1 + x + x^2 + x^3 + x^4 + x^5 * A(x/(1 - x)) / (1 - x)^2.

Original entry on oeis.org

1, 1, 1, 1, 1, 1, 3, 7, 15, 31, 63, 129, 277, 651, 1703, 4859, 14581, 44711, 138053, 427709, 1334461, 4226501, 13724063, 46110643, 161210421, 586729441, 2213187623, 8591628435, 34081480017, 137398121611, 561199251633, 2320442726999, 9722362801575
Offset: 0

Views

Author

Ilya Gutkovskiy, Feb 18 2022

Keywords

Crossrefs

Programs

  • Mathematica
    nmax = 32; A[] = 0; Do[A[x] = 1 + x + x^2 + x^3 + x^4 + x^5 A[x/(1 - x)]/(1 - x)^2 + O[x]^(nmax + 1) // Normal, nmax + 1]; CoefficientList[A[x], x]
    a[n_] := a[n] = If[n < 5, 1, Sum[Binomial[n - 4, k + 1] a[k], {k, 0, n - 5}]]; Table[a[n], {n, 0, 32}]

Formula

a(0) = ... = a(4) = 1; a(n) = Sum_{k=0..n-5} binomial(n-4,k+1) * a(k).

A351755 G.f. A(x) satisfies: A(x) = 1 + x + x^2 + x^3 + x^4 + x^5 + x^6 * A(x/(1 - x)) / (1 - x)^2.

Original entry on oeis.org

1, 1, 1, 1, 1, 1, 1, 3, 7, 15, 31, 63, 127, 257, 535, 1187, 2891, 7751, 22331, 66997, 204473, 626917, 1922395, 5899579, 18192715, 56739881, 180434023, 590010059, 1997588833, 7026454733, 25650892255, 96720885037, 374163527473, 1475021500693, 5893462132221
Offset: 0

Views

Author

Ilya Gutkovskiy, Feb 18 2022

Keywords

Crossrefs

Programs

  • Mathematica
    nmax = 34; A[] = 0; Do[A[x] = 1 + x + x^2 + x^3 + x^4 + x^5 + x^6 A[x/(1 - x)]/(1 - x)^2 + O[x]^(nmax + 1) // Normal, nmax + 1]; CoefficientList[A[x], x]
    a[n_] := a[n] = If[n < 6, 1, Sum[Binomial[n - 5, k + 1] a[k], {k, 0, n - 6}]]; Table[a[n], {n, 0, 34}]

Formula

a(0) = ... = a(5) = 1; a(n) = Sum_{k=0..n-6} binomial(n-5,k+1) * a(k).
Showing 1-3 of 3 results.