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.

A354013 Expansion of e.g.f. 1/(1 + log(1-x) * (1 - log(1-x))).

Original entry on oeis.org

1, 1, 5, 32, 278, 3014, 39226, 595608, 10335888, 201785688, 4377151464, 104444584848, 2718748442208, 76668029954736, 2328328726108368, 75759574181169792, 2629417097250852480, 96963968323279825920, 3786037089608099128320, 156041617540423798782720
Offset: 0

Views

Author

Seiichi Manyama, May 14 2022

Keywords

Crossrefs

Programs

  • PARI
    my(N=20, x='x+O('x^N)); Vec(serlaplace(1/(1+log(1-x)*(1-log(1-x)))))
    
  • PARI
    a_vector(n) = my(v=vector(n+1)); v[1]=1; for(i=1, n, v[i+1]=sum(j=1, i, (j-1)!*(1+2*sum(k=1, j-1, 1/k))*binomial(i, j)*v[i-j+1])); v;
    
  • PARI
    a(n) = sum(k=0, n, k!*fibonacci(k+1)*abs(stirling(n, k, 1)));

Formula

a(0) = 1; a(n) = Sum_{k=1..n} A000776(k-1) * binomial(n,k) * a(n-k).
a(n) = Sum_{k=0..n} k! * Fibonacci(k+1) * |Stirling1(n,k)|.
a(n) ~ n! / (sqrt(5) * exp((sqrt(5)-1)/2) * (1 - exp((1-sqrt(5))/2))^(n+1)). - Vaclav Kotesovec, May 15 2022

A358031 Expansion of e.g.f. (1 - log(1-x))/(1 + log(1-x) * (1 - log(1-x))).

Original entry on oeis.org

1, 2, 8, 52, 450, 4878, 63474, 963744, 16724016, 326497632, 7082393136, 168995017200, 4399028766192, 124051494462816, 3767315220903072, 122581568808533760, 4254486275273419008, 156890997080103149568, 6125936704495619486976, 252480641031903073955328
Offset: 0

Views

Author

Seiichi Manyama, Oct 25 2022

Keywords

Crossrefs

Programs

  • Maple
    f:= proc(n) local k; add(k!*combinat:-fibonacci(k+2)*abs(Stirling1(n,k)),k=0..n) end proc:
    map(f, [$0..30]); # Robert Israel, Oct 25 2022
  • Mathematica
    With[{nn=20},CoefficientList[Series[(1-Log[1-x])/(1+Log[1-x](1-Log[1-x])),{x,0,nn}],x] Range[ 0,nn]!] (* Harvey P. Dale, Jan 25 2024 *)
  • PARI
    my(N=20, x='x+O('x^N)); Vec(serlaplace((1-log(1-x))/(1+log(1-x)*(1-log(1-x)))))
    
  • PARI
    a(n) = sum(k=0, n, k!*fibonacci(k+2)*abs(stirling(n, k, 1)));

Formula

a(n) = Sum_{k=0..n} k! * Fibonacci(k+2) * |Stirling1(n,k)|.
a(n) = A354013(n) + A354018(n).
Showing 1-2 of 2 results.