OFFSET
1,1
LINKS
Hans Havermann, Table of n, a(n) for n = 1..530
MATHEMATICA
sumin[n_, k_] := Mod[Sum[If[GCD[i, n] == 1, PowerMod[i, k, n], 0], {i, 1, n}], n]; Select[Range[100], sumin[#, #] > 0 &]
CROSSREFS
KEYWORD
nonn
AUTHOR
José María Grau Ribas, Oct 07 2015
STATUS
approved