OFFSET
1,1
COMMENTS
Zeros occurring on composite n are rare: 42 and 4718 are the first two such positions.
It seems that many nonzero squares occur on square n.
LINKS
Antti Karttunen, Table of n, a(n) for n = 1..11550
PROG
(PARI)
up_to = 11550;
DirInverseCorrect(v) = { my(u=vector(#v)); u[1] = (1/v[1]); for(n=2, #v, u[n] = (-u[1]*sumdiv(n, d, if(d<n, v[n/d]*u[d], 0)))); (u) }; \\ Compute the Dirichlet inverse of the sequence given in input vector v.
A342002(n) = { my(s=0, m=1, p=2, e); while(n, e = (n%p); m *= p^(e>0); s += (e/p); n = n\p; p = nextprime(1+p)); (s*m); };
v342417 = DirInverseCorrect(vector(up_to, n, A342002(n)));
A342417(n) = v342417[n];
CROSSREFS
KEYWORD
sign
AUTHOR
Antti Karttunen, Mar 13 2021
STATUS
approved