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 A155575 #4 Jul 14 2012 11:32:23 %S A155575 29,41,45,61,89,101,109,116,145,149,164,180,181,205,225,229,241,244, %T A155575 245,261,269,281,305,349,356,369,389,401,404,405,409,421,436,445,449, %U A155575 461,464,505,509,521,541,545,549,569,580,596,601,641,656,661,701,709,720 %N A155575 Intersection of A000404 and A154778: N = a^2 + b^2 = c^2 + 5d^2 for some positive integers a,b,c,d. %C A155575 Subsequence of A155565 (where a,b,c,d may be zero). %o A155575 (PARI) isA155575(n,/* optional 2nd arg allows us to get other sequences */c=[5,1]) = { for(i=1,#c, for(b=1,sqrtint((n-1)\c[i]), issquare(n-c[i]*b^2) & next(2)); return);1} %o A155575 for( n=1,999, isA155575(n) & print1(n",")) %Y A155575 Cf. A000404, A154777, A092572, A097268, A154778, A155716, A155717, A155560-A155578. %K A155575 easy,nonn %O A155575 1,1 %A A155575 _M. F. Hasler_, Jan 25 2009