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 A104636 #9 Sep 06 2012 19:33:53 %S A104636 2,6,8,14,18,20,26,30,36,44,48,50,54,56,68,74,78,86,90,96,98,114,116, %T A104636 120,128,134,138,140,146,156,158,168,174,176,186,194,198,200,204,210, %U A104636 216,224,228,230,254,260,270,278,284,288,296,300,306,308,320,326,330 %N A104636 Even n such that 2n+1 is prime. %C A104636 If q = 2*n + 1 is prime, and n is even, q divides (n!)^2 + 1. - _Arkadiusz Wesolowski_, Sep 06 2012 %H A104636 T. D. Noe, <a href="/A104636/b104636.txt">Table of n, a(n) for n = 1..1000</a> %t A104636 Select[Range[2, 300, 2], PrimeQ[2*# + 1] &] %Y A104636 Cf. A005097, A104635. %K A104636 easy,nonn %O A104636 1,1 %A A104636 _Zak Seidov_, Mar 18 2005 %E A104636 a(48)-a(57) from _Arkadiusz Wesolowski_, Sep 06 2012