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 A281295 #6 Sep 08 2022 08:46:18 %S A281295 2,3,5,7,11,13,17,19,23,29,31,37,41,43,59,61,67,71,73,79,83,89,97,101, %T A281295 107,109,113,127,131,137,139,149,151,157,167,173,179,181,191,193,197, %U A281295 211,223,227,229,233,239,241,251,263,271,277,281,283,293,307,313,317 %N A281295 Primes which cannot be written as x^2 + 11*y^2, where x, y > 0. %C A281295 Integers n that cannot be expressed as the product of two numbers of the form a + b*sqrt(-11), where a > 0 and b >= 0 (excluding 1 and n). %F A281295 a(n) ~ 6/5 * n log n. %o A281295 (Magma) Sort([11] cat [p: p in PrimesUpTo(317) | NormEquation(11, p) eq false]); %Y A281295 Cf. A033209. %K A281295 nonn %O A281295 1,1 %A A281295 _Arkadiusz Wesolowski_, Jan 19 2017