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 A175600 #10 Aug 18 2018 08:33:25 %S A175600 53,149,293,389,773,1109,1493,1637,1733,2309,2693,2837,3413,3989,4133, %T A175600 4373,4517,5189,5717,5813,6197,6389,7013,7109,8069,8117,9173,9749, %U A175600 10709,10853,11813,12149,12197,12437,12917,13829,13877,14549,15077,15173 %N A175600 Primes of form 4k+1 where k is a Pythagorean prime. %C A175600 "Double-Pythagorean" primes: primes of form 4k+1 with k prime of form 4m+1. %C A175600 All terms are congruent to 5 modulo 48. - _Zak Seidov_, Jun 05 2014 %e A175600 53 = A002144(7) = 4*13 + 1, 13 = A002144(2); %e A175600 149 = A002144(16) = 4*37 + 1, 37 = A002144(5). %t A175600 se=Select[Range[5,100000,4],PrimeQ]; (* se=A002144 *) %t A175600 se2=Select[se,MemberQ[se,(#-1)/4]&] %t A175600 (* (se2-1)/4 = intersection (A005098, A002144) *) %Y A175600 Cf. A002144 (Pythagorean primes: primes of form 4n+1), A005098 (Numbers n such that 4n+1 is prime). %K A175600 nonn %O A175600 1,1 %A A175600 _Zak Seidov_, Jul 22 2010