OFFSET
1,2
LINKS
Seiichi Manyama, Table of n, a(n) for n = 1..10000
Eric Weisstein's World of Mathematics, Totient Function.
PROG
(PARI) a(n) = sum(k=1, n, eulerphi(k*n));
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, May 07 2024
STATUS
approved