This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A362225 #17 May 18 2023 19:42:34 %S A362225 17,113,193,241,353,641,1873,3361,5281,8513,10753,16433,17713,18593, %T A362225 21841,25873,34961,80273,92753,107201,111521,117041,134401,158113, %U A362225 168673,172721,182353,195121,211313,217361,221953,239201,279073,376001,394241 %N A362225 Primes of the form (2*p^2 + 1)/3 where p is a prime > 3. %C A362225 The corresponding p values are the odd terms of A175256. %F A362225 a(n) = (2*A175255(n+1)+1)/3. %e A362225 17 is a term since for p=5, (2*p^2 + 1)/3 = (2*5^2 + 1)/3 = 17 and 17 is prime. %t A362225 Select[(2*Prime[Range[3, 140]]^2 + 1)/3, PrimeQ] (* _Amiram Eldar_, May 18 2023 *) %o A362225 (PARI) forprime(p=5, 1000, my(Ap=floor((2*p^2+1)/3)); if(isprime(Ap), print1(Ap,", "))) %Y A362225 Cf. A175255, A175256. %K A362225 nonn %O A362225 1,1 %A A362225 _Alain Rocchelli_, Apr 11 2023