OFFSET
1,3
LINKS
Antti Karttunen, Table of n, a(n) for n = 1..16384
PROG
(PARI) a(n) = my(sn = sigma(n)); gcd(sn, eulerphi(sn)); \\ Michel Marcus, Nov 23 2017
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, Nov 22 2017
STATUS
approved