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A358679
Dirichlet inverse of the characteristic function of A061345, odd prime powers.
1
1, 0, -1, 0, -1, 0, -1, 0, 0, 0, -1, 0, -1, 0, 2, 0, -1, 0, -1, 0, 2, 0, -1, 0, 0, 0, 0, 0, -1, 0, -1, 0, 2, 0, 2, 0, -1, 0, 2, 0, -1, 0, -1, 0, -1, 0, -1, 0, 0, 0, 2, 0, -1, 0, 2, 0, 2, 0, -1, 0, -1, 0, -1, 0, 2, 0, -1, 0, 2, 0, -1, 0, -1, 0, -1, 0, 2, 0, -1, 0, 0, 0, -1, 0, 2, 0, 2, 0, -1, 0, 2, 0, 2, 0, 2, 0, -1, 0, -1, 0, -1, 0, -1, 0, -6
OFFSET
1,15
LINKS
FORMULA
a(1) = 1, and for n > 1, a(n) = -Sum_{d|n, d<n} A174275(n/d) * a(d).
PROG
(PARI)
A174275(n) = ((n%2)&&isprimepower(n));
memoA358679 = Map();
A358679(n) = if(1==n, 1, my(v); if(mapisdefined(memoA358679, n, &v), v, v = -sumdiv(n, d, if(d<n, A174275(n/d)*A358679(d), 0)); mapput(memoA358679, n, v); (v)));
CROSSREFS
Sequence in context: A140581 A137277 A039975 * A016253 A286998 A097796
KEYWORD
sign
AUTHOR
Antti Karttunen, Dec 23 2022
STATUS
approved