OFFSET
1,1
COMMENTS
a(5) > 10^7.
MATHEMATICA
Select[ Prime@ Range@ 30, Mod[ RamanujanTau@#, # - 1] == 0 &] (* Robert G. Wilson v, Feb 11 2018 *)
PROG
(PARI) isok(p) = isprime(p) && !(ramanujantau(p) % (p-1)); \\ Michel Marcus, Feb 05 2018
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Seiichi Manyama, Feb 04 2018
STATUS
approved