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.

A141312 Inverse Euler transform of A003480.

Original entry on oeis.org

1, 2, 4, 12, 31, 92, 256, 772, 2291, 7000, 21476, 66804, 208935, 658924, 2088628, 6656820, 21306270, 68468796, 220776444, 714117012, 2316229821, 7531561676, 24545492916, 80160031076, 262279882239, 859660694960, 2822177751148, 9278647613760, 30547880467863
Offset: 0

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Author

Jean-Yves Thibon (jyt(AT)univ-mlv.fr), Jun 26 2008

Keywords

Comments

Dimensions of the graded components of the primitive Lie algebra of the Hopf algebra of noncommutative multisymmetric functions of level 2.

Crossrefs

Cf. A003480.

Programs

  • Maple
    EULERi(INVERT([seq(n+1,n=1..20)]));
  • Mathematica
    terms = 29;
    mob[m_, n_] := If[Mod[m, n] == 0, MoebiusMu[m/n], 0];
    EULERi[b_] := Module[{a, c, i, d}, c = {}; For[i=1, i <= Length[b], i++, c = Append[c, i b[[i]] - Sum[c[[d]] b[[i-d]], {d, 1, i-1}]]]; a = {}; For[i = 1, i <= Length[b], i++, a = Append[a, (1/i) Sum[mob[i, d] c[[d]], {d, 1, i}]]]; Return[a]];
    Join[{1}, EULERi[LinearRecurrence[{4, -2}, {2, 7}, terms-1]]] (* Jean-François Alcover, Nov 25 2018 *)

Formula

a(n) ~ (2 + sqrt(2))^n / n. - Vaclav Kotesovec, Oct 09 2019

Extensions

More terms from Alois P. Heinz, Feb 20 2017