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.

A107895 Euler transform of n!.

Original entry on oeis.org

1, 1, 3, 9, 36, 168, 961, 6403, 49302, 430190, 4199279, 45326013, 535867338, 6884000262, 95453970483, 1420538043009, 22579098396600, 381704267100888, 6837775526561031, 129377310771795789, 2578101967764973314, 53965231260126083854, 1183813954026245944519
Offset: 0

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Author

Thomas Wieder, May 26 2005

Keywords

Crossrefs

Programs

  • Maple
    EulerTrans := proc(p) local b; b := proc(n) option remember; local d, j;
    `if`(n=0,1, add(add(d*p(d),d=numtheory[divisors](j)) *b(n-j),j=1..n)/n) end end:
    A107895 := EulerTrans(n->n!):  seq(A107895(n),n=0..20);
    # After Alois P. Heinz, A000335.  [Peter Luschny, Jul 07 2011]
  • Mathematica
    EulerTrans[p_] := Module[{b}, b[n_] := b[n] = Module[{d, j}, If[n == 0, 1, Sum[Sum[d*p[d], {d, Divisors[j]}]*b[n-j], {j, 1, n}]/n]]; b]; A107895 = EulerTrans[Factorial]; Table[A107895[n], {n, 0, 22}] (* Jean-François Alcover, Feb 25 2014, after Alois P. Heinz *)

Formula

a(n) ~ n! * (1 + 1/n + 3/n^2 + 12/n^3 + 66/n^4 + 450/n^5 + 3679/n^6 + 35260/n^7 + 388511/n^8 + 4844584/n^9 + 67502450/n^10), for next coefficients see A248871. - Vaclav Kotesovec, Mar 14 2015
G.f.: Product_{n>=1} 1/(1-x^n)^(n!). - Vaclav Kotesovec, Aug 04 2015