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 1-4 of 4 results.

A353995 Expansion of e.g.f. 1/(1 - x)^(exp(x) - 1).

Original entry on oeis.org

1, 0, 2, 6, 30, 185, 1315, 10682, 97692, 991797, 11060413, 134368344, 1766007122, 24963786003, 377633418279, 6086719267852, 104134471945368, 1884698592318537, 35976835400864745, 722386383476096128, 15220456179011671358, 335769403850849998439
Offset: 0

Views

Author

Seiichi Manyama, May 13 2022

Keywords

Crossrefs

Programs

  • Mathematica
    With[{nn=30},CoefficientList[Series[1/(1-x)^(Exp[x]-1),{x,0,nn}],x] Range[0,nn]!] (* Harvey P. Dale, Aug 03 2025 *)
  • PARI
    my(N=30, x='x+O('x^N)); Vec(serlaplace(1/(1-x)^(exp(x)-1)))
    
  • PARI
    my(N=30, x='x+O('x^N)); Vec(serlaplace(exp(-log(1-x)*(exp(x)-1))))

Formula

E.g.f.: exp( -log(1 - x) * (exp(x) - 1) ).
a(0) = 1; a(n) = Sum_{k=1..n} A052863(k) * binomial(n-1,k-1) * a(n-k).
a(n) ~ n! * n^(exp(1)-2) / Gamma(exp(1)-1) * (1 - (exp(1)-2)*exp(1)*log(n)/n). - Vaclav Kotesovec, May 13 2022

A353994 Expansion of e.g.f. 1/(1 + log(1 - x) * (exp(x) - 1)).

Original entry on oeis.org

1, 0, 2, 6, 42, 305, 2815, 29792, 362432, 4952481, 75239143, 1257202584, 22918653428, 452620972245, 9626556838015, 219367419292972, 5332164894151648, 137709755844024929, 3765736630207259055, 108696751776637007080, 3302628833563666988740
Offset: 0

Views

Author

Seiichi Manyama, May 13 2022

Keywords

Crossrefs

Programs

  • PARI
    my(N=30, x='x+O('x^N)); Vec(serlaplace(1/(1+log(1-x)*(exp(x)-1))))

Formula

a(0) = 1; a(n) = Sum_{k=1..n} A052863(k) * binomial(n,k) * a(n-k).

A381105 Expansion of e.g.f. log(1-x)^2 * (exp(x) - 1) / 2.

Original entry on oeis.org

0, 0, 0, 3, 18, 95, 540, 3479, 25550, 212106, 1968435, 20211664, 227570871, 2788446011, 36941736832, 526201686373, 8019670404980, 130221159155540, 2244376179923685, 40921210296083610, 786941965401130321, 15918834017469062277, 337908155040286890290, 7510104219030171089935
Offset: 0

Views

Author

Seiichi Manyama, Feb 14 2025

Keywords

Crossrefs

Programs

  • PARI
    a(n) = sum(k=0, n-1, binomial(n, k)*abs(stirling(k, 2, 1)));

Formula

a(n) = Sum_{k=0..n-1} binomial(n,k) * |Stirling1(k,2)|.
a(n) = A381021(n) - A000254(n-1).

A381106 Expansion of e.g.f. -log(1-x)^3 * (exp(x) - 1) / 6.

Original entry on oeis.org

0, 0, 0, 0, 4, 40, 320, 2555, 21728, 200802, 2024510, 22221485, 264453750, 3396686865, 46873789235, 692049842575, 10889098371032, 181952854080860, 3218431205690356, 60087159752141449, 1180916015576750386, 24372799835934758327, 527084149497398472485, 11919591185373007970251
Offset: 0

Views

Author

Seiichi Manyama, Feb 14 2025

Keywords

Crossrefs

Programs

  • PARI
    a(n) = sum(k=0, n-1, binomial(n, k)*abs(stirling(k, 3, 1)));

Formula

a(n) = Sum_{k=0..n-1} binomial(n,k) * |Stirling1(k,3)|.
a(n) = A381022(n) - A000399(n).
Showing 1-4 of 4 results.