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 1-2 of 2 results.

A376386 Expansion of e.g.f. (1/x) * Series_Reversion( x*(1 + x*log(1-x))^3 ).

Original entry on oeis.org

1, 0, 6, 9, 600, 3510, 204372, 2617020, 152727936, 3319236144, 203151929040, 6485780434320, 425284393933440, 18190896271479360, 1291781802823916544, 69545182272420909600, 5374429456543444177920, 348502600060029871948800, 29344904433432469953368064
Offset: 0

Views

Author

Seiichi Manyama, Sep 22 2024

Keywords

Crossrefs

Programs

  • PARI
    my(N=20, x='x+O('x^N)); Vec(serlaplace(serreverse(x*(1+x*log(1-x))^3)/x))
    
  • PARI
    a(n) = 3*n!*sum(k=0, n\2, (3*n+k+2)!*abs(stirling(n-k, k, 1))/(n-k)!)/(3*n+3)!;

Formula

E.g.f. A(x) satisfies A(x) = 1/(1 + x*A(x) * log(1 - x*A(x)))^3.
E.g.f.: B(x)^3, where B(x) is the e.g.f. of A371232.
a(n) = (3 * n!/(3*n+3)!) * Sum_{k=0..floor(n/2)} (3*n+k+2)! * |Stirling1(n-k,k)|/(n-k)!.

A376436 Expansion of e.g.f. (1/x) * Series_Reversion( x*(1 + x^2*log(1-x))^2 ).

Original entry on oeis.org

1, 0, 0, 12, 24, 80, 11160, 87696, 715680, 62337600, 1065980160, 15842534400, 1109943362880, 31591940440320, 731706348941568, 46767587926752000, 1889337264901632000, 61735665488234250240, 3896148715287564902400, 201584132714100384460800, 8661099107269708639948800, 567405718655558932535500800
Offset: 0

Views

Author

Seiichi Manyama, Sep 22 2024

Keywords

Crossrefs

Programs

  • PARI
    my(N=30, x='x+O('x^N)); Vec(serlaplace(serreverse(x*(1+x^2*log(1-x))^2)/x))
    
  • PARI
    a(n) = 2*n!*sum(k=0, n\3, (2*n+k+1)!*abs(stirling(n-2*k, k, 1))/(n-2*k)!)/(2*n+2)!;

Formula

E.g.f. A(x) satisfies A(x) = 1/(1 + x^2*A(x)^2 * log(1 - x*A(x)))^2.
E.g.f.: B(x)^2, where B(x) is the e.g.f. of A371235.
a(n) = (2 * n!/(2*n+2)!) * Sum_{k=0..floor(n/3)} (2*n+k+1)! * |Stirling1(n-2*k,k)|/(n-2*k)!.
Showing 1-2 of 2 results.