OFFSET
0,3
LINKS
Seiichi Manyama, Table of n, a(n) for n = 0..10000
N. J. A. Sloane, Transforms
FORMULA
MATHEMATICA
b[n_] := If[n == 1, 1, Product[{p, e} = pe; If[2 == p, e--, If[e > 1, p = 0, p = -1]]; p^e, {pe, FactorInteger[n]}]];
etr[p_] := Module[{b}, b[n_] := b[n] = If[n == 0, 1, Sum[Sum[d*p[d], {d, Divisors[j]}]*b[n - j], {j, 1, n}]/n]; b];
a = etr[b];
a /@ Range[0, 100] (* Jean-François Alcover, Oct 01 2019 *)
CROSSREFS
KEYWORD
sign,look
AUTHOR
Seiichi Manyama, Nov 05 2018
STATUS
approved