OFFSET
1,2
LINKS
Antti Karttunen, Table of n, a(n) for n = 1..16384
MATHEMATICA
Array[GCD[#, EulerPhi[DivisorSigma[1, #]]] &, 105] (* Michael De Vlieger, Nov 23 2017 *)
PROG
(PARI) a(n) = gcd(n, eulerphi(sigma(n))); \\ Michel Marcus, Nov 23 2017
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, Nov 22 2017
STATUS
approved