OFFSET
1,1
LINKS
Antti Karttunen, Table of n, a(n) for n = 1..20000
PROG
(PARI)
up_to = 16384;
DirInverse(v) = { my(u=vector(#v)); u[1] = (1/v[1]); for(n=2, #v, u[n] = -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.
A083254(n) = (2*eulerphi(n)-n);
v323912 = DirInverse(vector(up_to, n, A083254(n)));
A323912(n) = v323912[n];
CROSSREFS
KEYWORD
sign
AUTHOR
Antti Karttunen, Feb 12 2019
STATUS
approved