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 A228123 #13 Sep 23 2023 03:39:02
%S A228123 1,10,86,581,4148,31984,261080,2208196,19132652,168806740,1510676802
%N A228123 Number of primes generated from Euler's polynomial x^2 + x + 41 from x = 1 to 10^n.
%F A228123 a(n) = A331876(n) - 1. - _Amiram Eldar_, Sep 23 2023
%e A228123 a(4) = 4148 because the number of primes generated from Euler's polynomial x^2 + x + 41 from x = 1 to 10^4 are 4148.
%t A228123 a = 0; n = 1; t = {}; Do[If[PrimeQ[x^2 + x + 41], a = a + 1]; If[Mod[x, n] == 0, n = n*10; AppendTo[t, a]], {x, 1, 1000000000}]; t
%Y A228123 Cf. A005846, A056561, A331876.
%K A228123 nonn,more
%O A228123 0,2
%A A228123 _Shyam Sunder Gupta_, Aug 11 2013
%E A228123 a(10) from _Amiram Eldar_, Sep 23 2023