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 A247101 #14 Sep 08 2022 08:46:09 %S A247101 2,11,41,59,181,379,571,659,1429,1439,1721,1879,2029,2239,2351,2381, %T A247101 2579,2671,3209,3581,4159,4229,4271,4969,4999,6299,6451,6551,7349, %U A247101 7841,10391,10399,11059,11551,12841,13049,13159,13619,14071,15329,15581,15889,16811,17231,17749,18719,20219 %N A247101 Primes p such that 2*(p^2-1) - 1 and 2*(p^2-1) + 1 are also primes. %C A247101 Subsequence of prime terms of A249446. %e A247101 2 is in this sequence because 2, 2*(2^2-1) - 1 = 5 and 2*(2^2-1) + 1 = 7 are all primes. %t A247101 Select[Range[25000], PrimeQ[#] && PrimeQ[2 #^2 - 3] && PrimeQ[2 #^2 - 1] &] (* _Vincenzo Librandi_, Nov 19 2014 *) %o A247101 (Magma) [ n: n in [1..22000] | IsPrime(n) and IsPrime(2*(n^2-1)-1) and IsPrime(2*(n^2-1)+1) ]; %Y A247101 Cf. A249446. %K A247101 nonn %O A247101 1,1 %A A247101 _Juri-Stepan Gerasimov_, Nov 18 2014