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.

A355466 Expansion of Sum_{k>=0} (k^k * x)^k/(1 - k^k * x)^(k+1).

Original entry on oeis.org

1, 2, 19, 19879, 4297094601, 298028721578591321, 10314430386430205371442173873, 256923580889667562995278943476559835493321, 6277101737079381674883855772624745947410338680458857322625
Offset: 0

Views

Author

Seiichi Manyama, Jul 03 2022

Keywords

Crossrefs

Programs

  • PARI
    my(N=10, x='x+O('x^N)); Vec(sum(k=0, N, (k^k*x)^k/(1-k^k*x)^(k+1)))
    
  • PARI
    my(N=10, x='x+O('x^N)); Vec(serlaplace(sum(k=0, N, exp(k^k*x)*(k^k*x)^k/k!)))
    
  • PARI
    a(n) = sum(k=0, n, k^(k*n)*binomial(n, k));

Formula

E.g.f.: Sum_{k>=0} exp(k^k * x) * (k^k * x)^k/k!.
a(n) = Sum_{k=0..n} k^(k*n) * binomial(n,k).

A355469 Expansion of Sum_{k>=0} (k^3 * x/(1 - k^3 * x))^k.

Original entry on oeis.org

1, 1, 65, 20708, 18383828, 34898769936, 121324513279512, 697408243146701056, 6165037130760825320768, 79390334273383043609851520, 1428007543233019703635181454080, 34693490969752778534655707874499584, 1107666867764009444258160579726602423808
Offset: 0

Views

Author

Seiichi Manyama, Jul 03 2022

Keywords

Crossrefs

Programs

  • PARI
    my(N=20, x='x+O('x^N)); Vec(sum(k=0, N, (k^3*x/(1-k^3*x))^k))
    
  • PARI
    a(n) = if(n==0, 1, sum(k=1, n, k^(3*n)*binomial(n-1, k-1)));

Formula

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

A355493 Expansion of Sum_{k>=0} (k^3 * x)^k/(1 - x)^(k+1).

Original entry on oeis.org

1, 2, 67, 19879, 16856337, 30601661681, 101743314190033, 559257425236996361, 4726837695171258085569, 58192258417571877186113281, 1000581709943568968705788233921, 23236157618902718144948494353385025, 709080642850925779233576351761544968833
Offset: 0

Views

Author

Seiichi Manyama, Jul 04 2022

Keywords

Crossrefs

Programs

  • PARI
    my(N=20, x='x+O('x^N)); Vec(sum(k=0, N, (k^3*x)^k/(1-x)^(k+1)))
    
  • PARI
    my(N=20, x='x+O('x^N)); Vec(serlaplace(exp(x)*sum(k=0, N, (k^3*x)^k/k!)))
    
  • PARI
    a(n) = sum(k=0, n, k^(3*k)*binomial(n, k));

Formula

E.g.f.: exp(x) * Sum_{k>=0} (k^3 * x)^k/k!.
a(n) = Sum_{k=0..n} k^(3*k) * binomial(n,k).
Showing 1-3 of 3 results.