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 A091271 #13 Jul 10 2018 18:51:02 %S A091271 2,4,5,9,10,14,16,19,21,24,26,31,35,39,40,45,59,60,65,74,79,80,86,91, %T A091271 100,105,109,114,115,116,119,124,126,129,130,131,135,136,145,149,150, %U A091271 151,159,170,171,175,179,180,185,186,189,194,199,205,206,210,219,221 %N A091271 Numbers k such that 4*k^2-11 is a prime. %H A091271 Robert Israel, <a href="/A091271/b091271.txt">Table of n, a(n) for n = 1..10000</a> %F A091271 a(n) = A090696(n)/2. %p A091271 select(t -> isprime(4*t^2-11), [$2..1000]); # _Robert Israel_, Jul 10 2018 %o A091271 (PARI) is(n) = ispseudoprime(4*n^2-11) \\ _Felix Fröhlich_, Jul 10 2018 %o A091271 (GAP) Filtered([2..230],n->IsPrime(4*n^2-11)); # _Muniru A Asiru_, Jul 10 2018 %Y A091271 A091272 gives primes, A091273 gives prime index. %K A091271 nonn %O A091271 1,1 %A A091271 _Ray Chandler_, Dec 27 2003 %E A091271 Offset changed by _Robert Israel_, Jul 10 2018