1,1

Table of n, a(n) for n=1..39.

A025475(n) - 2 is prime

4 is here since 4-2=2, 243=3^5 is here because 241 is prime

Select[Range[130000], !PrimeQ[#]&&PrimePowerQ[#]&&PrimeQ[#-2]&] (* Harvey P. Dale, Oct 07 2020 *)

A025475.

Sequence in context: A336230 A130283 A065739 * A277900 A344701 A182988

Adjacent sequences: A053701 A053702 A053703 * A053705 A053706 A053707

nonn

Labos Elemer, Feb 14 2000

Definition clarified by Harvey P. Dale, Oct 07 2020

approved