A378213 Dirichlet inverse of A140773.

1, -2, -2, 0, -2, 3, -2, 2, 0, 3, -2, 2, -2, 3, 3, -1, -2, 2, -2, 2, 3, 3, -2, -4, 0, 3, 2, 2, -2, -2, -2, 0, 3, 3, 3, -3, -2, 3, 3, -4, -2, -2, -2, 2, 2, 3, -2, 0, 0, 2, 3, 2, -2, -4, 3, -4, 3, 3, -2, -6, -2, 3, 2, 0, 3, -2, -2, 2, 3, -2, -2, -2, -2, 3, 2, 2, 3, -2, -2, 0, -1, 3, -2, -6, 3, 3, 3, -4, -2, -6, 3, 2, 3, 3, 3, 1

Offset

1,2

Links

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

Formula

a(1) = 1, and for n > 1, a(n) = -Sum_{d|n, d<n} A140773(n/d) * a(d).

Prog

(PARI)
A065043(n) = (1 - (bigomega(n)%2));
A038548(n) = sumdiv(n, d, A065043(d));
A140773(n) = sumdiv(n, d, A038548(d));
memoA378213 = Map();
A378213(n) = if(1==n, 1, my(v); if(mapisdefined(memoA378213, n, &v), v, v = -sumdiv(n, d, if(d<n, A140773(n/d)*A378213(d), 0)); mapput(memoA378213, n, v); (v)));

Crossrefs

Cf. A140773, A378214, A378215 (parity of terms).

Sequence in context: A099307 A361869 A256750 * A228430 A241533 A370885

Adjacent sequences: A378210 A378211 A378212 * A378214 A378215 A378216

Keyword

sign

Author

Antti Karttunen, Nov 22 2024

Status

approved