OFFSET
1,1
COMMENTS
Numbers k of the form 9m+3 such that k/3 = p^k, with p a prime and k >= 1.
FORMULA
a(n) = 3 * A137827(n).
MATHEMATICA
Select[Range[2000], Mod[#, 9] == 3 && PrimePowerQ[#/3] &] (* Amiram Eldar, Jun 15 2022 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, Jun 15 2022
STATUS
approved