OFFSET
1,1
COMMENTS
The corresponding p values are the odd terms of A175256.
FORMULA
a(n) = (2*A175255(n+1)+1)/3.
EXAMPLE
17 is a term since for p=5, (2*p^2 + 1)/3 = (2*5^2 + 1)/3 = 17 and 17 is prime.
MATHEMATICA
Select[(2*Prime[Range[3, 140]]^2 + 1)/3, PrimeQ] (* Amiram Eldar, May 18 2023 *)
PROG
(PARI) forprime(p=5, 1000, my(Ap=floor((2*p^2+1)/3)); if(isprime(Ap), print1(Ap, ", ")))
CROSSREFS
KEYWORD
nonn
AUTHOR
Alain Rocchelli, Apr 11 2023
STATUS
approved