A226999 Inverse Euler transform of A005169 (fountains of coins).

1, 0, 1, 1, 2, 3, 5, 8, 13, 21, 35, 55, 93, 149, 248, 403, 671, 1098, 1827, 3013, 5013, 8313, 13859, 23063, 38534, 64341, 107715, 180355, 302565, 507784, 853507, 1435415, 2416941, 4072272, 6868062, 11590807, 19577555, 33088481, 55964327, 94712212

Offset: 1

Author

R. J. Mathar, Jun 26 2013

Keywords

• nonn

Comments

If G005169(x) = Sum_{i>=0} A005169(n)*x^n is the generating function of A005169, the a(n) are defined through G005169(x) = Product_{n>=1} 1/(1-x^n)^a(n), the inverse Euler transform of A005169.

References

• Steven R. Finch, Mathematical Constants, Cambridge, 2003, p. 381.

Links

• Alois P. Heinz, Table of n, a(n) for n = 1..4178
• R. K. Guy, Letter to N. J. A. Sloane, Sep 25 1986.
• R. K. Guy, Letter to N. J. A. Sloane, 1987
• R. K. Guy, The strong law of small numbers. Amer. Math. Monthly 95 (1988), no. 8, 697-712.
• R. K. Guy, The strong law of small numbers. Amer. Math. Monthly 95 (1988), no. 8, 697-712. [Annotated scanned copy]

Crossrefs

Cf. A005169, A005170.

Programs

Mathematica

max = 100;
A005169 = Series[1 - Fold[Function[1 - x^#2/#1], 1, Range[max, 0, -1]], {x, 0, max}] // CoefficientList[#, x]&;
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]];
EULERi[A005169 // Rest] (* Jean-François Alcover, Jan 06 2020 *)

Formula

a(n) ~ 1 / (n * r^n), where r = A347901 = 0.57614876914275660229786857371993878235472466311897446868515653431946822937499... - Vaclav Kotesovec, Oct 09 2019