A378446 - OEIS

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A378446

Inverse Möbius transform of A083206, where A083206(n) is the number of ways of partitioning the divisors of n into two disjoint sets with equal sum.

0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 5, 0, 0, 0, 1, 0, 4, 0, 0, 0, 0, 0, 2, 0, 0, 0, 3, 0, 3, 0, 0, 0, 0, 0, 10, 0, 0, 0, 0, 0, 3, 0, 2, 0, 0, 0, 23, 0, 0, 0, 0, 0, 3, 0, 0, 0, 1, 0, 5, 0, 0, 0, 0, 0, 3, 0, 6, 0, 0, 0, 19, 0, 0, 0, 1, 0, 17, 0, 0, 0, 0, 0, 21, 0, 0, 0, 1, 0, 3, 0, 1, 0, 0, 0, 12

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,12

LINKS

Antti Karttunen, Table of n, a(n) for n = 1..20000

FORMULA

a(n) = Sum_{d|n} A083206(d).

PROG

(PARI)

A083206(n) = { my(p=1); fordiv(n, d, p *= ('x^d + 'x^-d)); (polcoeff(p, 0)/2); };

A378446(n) = sumdiv(n, d, A083206(d));

CROSSREFS