A305633 - OEIS

A305633

Expansion of Sum_{r not a perfect power} x^r/(1 + x^r).

0, 0, 1, 1, -1, 1, 1, 1, -1, 1, 1, 1, -2, 1, 1, 3, -1, 1, 2, 1, -2, 3, 1, 1, -3, 1, 1, 1, -2, 1, 1, 1, -1, 3, 1, 3, -3, 1, 1, 3, -3, 1, 1, 1, -2, 4, 1, 1, -4, 1, 2, 3, -2, 1, 3, 3, -3, 3, 1, 1, -4, 1, 1, 4, -1, 3, 1, 1, -2, 3, 1, 1, -3, 1, 1, 4, -2, 3, 1, 1, -4

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OFFSET

0,13

LINKS

Table of n, a(n) for n=0..80.

MATHEMATICA

nn=100;

wadQ[n_]:=n>1&&GCD@@FactorInteger[n][[All, 2]]==1;

ser=Sum[x^p/(1+x^p), {p, Select[Range[nn], wadQ]}];

Table[SeriesCoefficient[ser, {x, 0, n}], {n, nn}]

CROSSREFS