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.

A376382 Expansion of e.g.f. (1/x) * Series_Reversion( x*(1 - x*(exp(x) - 1))^3 ).

Original entry on oeis.org

1, 0, 6, 9, 588, 3435, 196038, 2504271, 143382648, 3105223155, 186676465890, 5932031027703, 382522369695876, 16267245179116971, 1137287705462533758, 60811389044325205695, 4631220227358066139248, 298002734705467572715491, 24748409310987998502582138
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*(exp(x)-1))^3)/x))
    
  • PARI
    a(n) = 3*n!*sum(k=0, n\2, (3*n+k+2)!*stirling(n-k, k, 2)/(n-k)!)/(3*n+3)!;

Formula

E.g.f. A(x) satisfies A(x) = 1/(1 - x*A(x) * (exp(x*A(x)) - 1))^3.
E.g.f.: B(x)^3, where B(x) is the e.g.f. of A371273.
a(n) = (3 * n!/(3*n+3)!) * Sum_{k=0..floor(n/2)} (3*n+k+2)! * Stirling2(n-k,k)/(n-k)!.

A376383 Expansion of e.g.f. ( (1/x) * Series_Reversion( x*(1 - x*(exp(x) - 1))^3 ) )^(2/3).

Original entry on oeis.org

1, 0, 4, 6, 368, 2170, 119712, 1542254, 86459200, 1884526578, 111718563680, 3566361530182, 227778981600480, 9716705596149578, 674774811779124448, 36153388845386205150, 2740217544109113107072, 176542121944523097148642, 14610965831419986026094816
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*(exp(x)-1))^3)/x)^(2/3)))
    
  • PARI
    a(n) = 2*n!*sum(k=0, n\2, (3*n+k+1)!*stirling(n-k, k, 2)/(n-k)!)/(3*n+2)!;

Formula

E.g.f.: B(x)^2, where B(x) is the e.g.f. of A371273.
a(n) = (2 * n!/(3*n+2)!) * Sum_{k=0..floor(n/2)} (3*n+k+1)! * Stirling2(n-k,k)/(n-k)!.
Showing 1-2 of 2 results.