login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A372568
a(n) = Sum_{d|n} A346242(d), where A346242 is the Dirichlet inverse of gcd(n, A276086(n)).
1
1, 0, -2, 0, 0, 2, 0, 0, 4, -4, 0, 0, 0, 0, -12, 0, 0, -8, 0, 0, 0, 0, 0, 0, -24, 0, -8, 0, 0, 32, 0, 0, 0, 0, -6, 4, 0, 0, 0, 0, 0, -6, 0, 0, 48, 0, 0, 0, -6, 4, 0, 0, 0, 24, -4, -6, 0, 0, 0, -16, 0, 0, -18, 0, 0, 0, 0, 0, 0, -24, 0, 0, 0, 0, 60, 0, -6, 0, 0, 0, 16, 0, 0, 0, -4, 0, 0, 0, 0, -160, -6, 0, 0, 0, 0, 0, 0, -42
OFFSET
1,3
COMMENTS
No odd terms after the initial 1.
PROG
(PARI)
A324198(n) = { my(m=1, p=2, orgn=n); while(n, m *= (p^min(n%p, valuation(orgn, p))); n = n\p; p = nextprime(1+p)); (m); };
memoA346242 = Map();
A346242(n) = if(1==n, 1, my(v); if(mapisdefined(memoA346242, n, &v), v, v = -sumdiv(n, d, if(d<n, A324198(n/d)*A346242(d), 0)); mapput(memoA346242, n, v); (v)));
A372568(n) = sumdiv(n, d, A346242(d));
CROSSREFS
Inverse Möbius transform of A346242.
Sequence in context: A138805 A316400 A061897 * A047919 A272624 A271223
KEYWORD
sign
AUTHOR
Antti Karttunen, May 24 2024
STATUS
approved