OFFSET
1,2
COMMENTS
A variant of A240667 without zeros.
LINKS
Antti Karttunen, Table of n, a(n) for n = 1..20000
EXAMPLE
a(6)=1 since sigma(6)=12 and sigma(11)=12 and gcd(6, 11) = 1.
PROG
(PARI) sigv(n) = select(i->sigma(i) == n, vector(n, i, i));
a(n) = gcd(sigv(sigma(n)));
CROSSREFS
KEYWORD
nonn
AUTHOR
Michel Marcus, Apr 23 2014
STATUS
approved