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.

A357028 E.g.f. satisfies A(x) = (1 - x * A(x))^log(1 - x * A(x)).

Original entry on oeis.org

1, 0, 2, 6, 82, 820, 13568, 235368, 5111748, 123205248, 3404436312, 103998026880, 3516027852456, 129715202957184, 5198615642907360, 224652658604613120, 10419411912935774736, 516120552745366247424, 27198524267826237745824
Offset: 0

Views

Author

Seiichi Manyama, Sep 09 2022

Keywords

Crossrefs

Programs

  • Mathematica
    m = 20; (* number of terms *)
    A[_] = 0;
    Do[A[x_] = (1 - x*A[x])^Log[1 - x*A[x]] + O[x]^m // Normal, {m}];
    CoefficientList[A[x], x]*Range[0, m - 1]! (* Jean-François Alcover, Sep 12 2022 *)
  • PARI
    a(n) = sum(k=0, n\2, (2*k)!*(n+1)^(k-1)*abs(stirling(n, 2*k, 1))/k!);

Formula

E.g.f. satisfies log(A(x)) = log(1 - x * A(x))^2.
a(n) = Sum_{k=0..floor(n/2)} (2*k)! * (n+1)^(k-1) * |Stirling1(n,2*k)|/k!.

A357037 E.g.f. satisfies A(x) = 1/(1 - x * A(x))^(log(1 - x * A(x))^2 / 6).

Original entry on oeis.org

1, 0, 0, 1, 6, 35, 295, 3304, 42112, 599724, 9657330, 174222576, 3464835726, 75208002792, 1771121398956, 44998593873024, 1226723273550720, 35714547582173280, 1106012915718532920, 36304411160854523520, 1259105580819317636280, 46007354360033491345920
Offset: 0

Views

Author

Seiichi Manyama, Sep 09 2022

Keywords

Crossrefs

Programs

  • Mathematica
    m = 22; (* number of terms *)
    A[_] = 0;
    Do[A[x_] = 1/(1 - x*A[x])^(Log[1 - x*A[x]]^2/6) + O[x]^m // Normal, {m}];
    CoefficientList[A[x], x]*Range[0, m - 1]! (* Jean-François Alcover, Sep 12 2022 *)
  • PARI
    a(n) = sum(k=0, n\3, (3*k)!*(n+1)^(k-1)*abs(stirling(n, 3*k, 1))/(6^k*k!));

Formula

E.g.f. satisfies log(A(x)) = -log(1 - x * A(x))^3 / 6.
a(n) = Sum_{k=0..floor(n/3)} (3*k)! * (n+1)^(k-1) * |Stirling1(n,3*k)|/(6^k * k!).

A357091 E.g.f. satisfies A(x) = 1/(1 - x * A(x))^(log(1 - x * A(x))^2 * A(x)).

Original entry on oeis.org

1, 0, 0, 6, 36, 210, 4590, 85344, 1353912, 30525384, 836587440, 22585438656, 676820305656, 23377203675072, 857981143380816, 33416782099297344, 1417453025671696320, 64371985604089220160, 3086958605328618687360, 157142856384519974847360
Offset: 0

Views

Author

Seiichi Manyama, Sep 11 2022

Keywords

Crossrefs

Programs

  • PARI
    a(n) = sum(k=0, n\3, (3*k)!*(n+k+1)^(k-1)*abs(stirling(n, 3*k, 1))/k!);

Formula

E.g.f. satisfies log(A(x)) = -log(1 - x * A(x))^3 * A(x).
a(n) = Sum_{k=0..floor(n/3)} (3*k)! * (n+k+1)^(k-1) * |Stirling1(n,3*k)|/k!.

A357093 E.g.f. satisfies A(x)^A(x) = 1/(1 - x * A(x))^(log(1 - x * A(x))^2).

Original entry on oeis.org

1, 0, 0, 6, 36, 210, 3150, 55104, 890232, 16735944, 386223120, 9790441056, 265867900056, 7943197796352, 260063260578576, 9156071916788544, 344740627648393920, 13880862578534022720, 595178180505073088640, 27035591386823290224000
Offset: 0

Views

Author

Seiichi Manyama, Sep 11 2022

Keywords

Crossrefs

Programs

  • PARI
    a(n) = sum(k=0, n\3, (3*k)!*(n-k+1)^(k-1)*abs(stirling(n, 3*k, 1))/k!);

Formula

E.g.f. satisfies A(x) * log(A(x)) = -log(1 - x * A(x))^3.
a(n) = Sum_{k=0..floor(n/3)} (3*k)! * (n-k+1)^(k-1) * |Stirling1(n,3*k)|/k!.
Showing 1-4 of 4 results.