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 1-5 of 5 results.

A349588 E.g.f. satisfies: A(x) * log(A(x)) = exp(x*A(x)) - 1.

Original entry on oeis.org

1, 1, 2, 8, 47, 367, 3592, 42317, 583522, 9223872, 164482761, 3267077365, 71540314562, 1712334954865, 44479256704898, 1246241906483516, 37465750470667023, 1202986323660907447, 41089436549405467096, 1487622596267089224901, 56907111260864275384346
Offset: 0

Views

Author

Seiichi Manyama, Nov 22 2021

Keywords

Crossrefs

Programs

  • Mathematica
    a[n_] := Sum[(n - k + 1)^(k - 1)*StirlingS2[n, k], {k, 0, n}]; Array[a, 21, 0] (* Amiram Eldar, Nov 23 2021 *)
  • PARI
    a(n) = sum(k=0, n, (n-k+1)^(k-1)*stirling(n, k, 2));

Formula

a(n) = Sum_{k=0..n} (n-k+1)^(k-1) * Stirling2(n,k).
a(n) ~ s * n^(n-1) / (sqrt(r*s - 1/(1 + log(s))) * exp(n) * r^n), where r = 0.4858893246242883887847088396703818017675758048583... and s = 3.016426175038226058288579473351450432292607021364... are roots of the system of equations exp(r*s) = 1 + s*log(s), exp(r*s)*r = 1 + log(s). - Vaclav Kotesovec, Nov 25 2021

A349589 E.g.f. satisfies: A(x) * log(A(x)) = 1 - exp(-x*A(x)).

Original entry on oeis.org

1, 1, 0, -4, -3, 87, 230, -4583, -27216, 434928, 4871719, -62913079, -1240374960, 12230778601, 426135019232, -2759957884648, -189393687667107, 479371576805751, 105233549909615798, 233116575802412969, -71022416772836562008, -574100485456271792020
Offset: 0

Views

Author

Seiichi Manyama, Nov 22 2021

Keywords

Crossrefs

Programs

  • Mathematica
    a[n_] := Sum[(-1)^(n - k)*(n - k + 1)^(k - 1)*StirlingS2[n, k], {k, 0, n}]; Array[a, 22, 0] (* Amiram Eldar, Nov 23 2021 *)
  • PARI
    a(n) = sum(k=0, n, (-1)^(n-k)*(n-k+1)^(k-1)*stirling(n, k, 2));

Formula

a(n) = Sum_{k=0..n} (-1)^(n-k) * (n-k+1)^(k-1) * Stirling2(n,k).

A357423 E.g.f. satisfies A(x) * exp(A(x)) = log(1 + x * exp(A(x))).

Original entry on oeis.org

0, 1, -1, -1, 10, 4, -384, 818, 29800, -205200, -3612000, 56042832, 556589232, -19091774352, -70128589608, 8044430218680, -25379500932864, -4055729067351552, 48310659088501248, 2334746679051721536, -58078273556262804480, -1420062892415588203776
Offset: 0

Views

Author

Seiichi Manyama, Sep 27 2022

Keywords

Crossrefs

Programs

  • PARI
    a(n) = sum(k=1, n, (n-k)^(k-1)*stirling(n, k, 1));

Formula

a(n) = Sum_{k=1..n} (n-k)^(k-1) * Stirling1(n,k).
E.g.f.: Series_Reversion( exp(-x) * (exp(x * exp(x)) - 1) ). - Seiichi Manyama, Sep 10 2024

A349600 E.g.f. satisfies: A(x)^A(x) = 1 + x*A(x)^2.

Original entry on oeis.org

1, 1, 2, 3, -20, -320, -2274, 5474, 487432, 8358480, 37944240, -2286868848, -81319780200, -1139790073968, 18382692073032, 1570867988794680, 42704382709868736, 55662087673489920, -49662902468183117760, -2360239974764654675904, -38098700311039336972800
Offset: 0

Views

Author

Seiichi Manyama, Nov 22 2021

Keywords

Crossrefs

Programs

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

Formula

a(n) = Sum_{k=0..n} (2*n-k+1)^(k-1) * Stirling1(n,k).

A355768 E.g.f. satisfies A(x)^(A(x)^2) = 1 + x*A(x).

Original entry on oeis.org

1, 1, -2, 6, -28, 260, -3948, 71120, -1392368, 29971008, -724981920, 19800726528, -603571233120, 20210951379840, -734663902256256, 28785160833254400, -1210241780559067392, 54390280325210271744, -2602745536670709682176, 132118736078618372579328
Offset: 0

Views

Author

Seiichi Manyama, Jul 16 2022

Keywords

Crossrefs

Programs

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

Formula

a(n) = Sum_{k=0..n} (n-2*k+1)^(k-1) * Stirling1(n,k).
Showing 1-5 of 5 results.