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 A136626 #9 Jul 04 2020 01:46:33 %S A136626 4,2,3,3,2,3,2,3,3,2,3,5,3,2,2,2,2,3,3,3,3,2,2,2,1,0,2,3,3,3,2,3,3,1, %T A136626 2,2,2,3,3,2,2,3,2,1,1,2,2,2,1,1,1,1,1,2,3,2,2,2,1,2,1,2,2,1,3,3,2,1, %U A136626 2,3,4,4,3,3,2,0,1,2,1,1,1,1,0,1,2,2,2,1,1,2,1,0,2,2,4,3,2,1,0,1,0,2 %N A136626 For every number n in Ulam's spiral the sequence gives the number of primes around it (number n excluded). %C A136626 In Ulam's lattice there are 8 numbers around any number. %e A136626 Numbers around 13 are 3, 12, 29, 30, 31, 32, 33, 14 -> 3, 29, 31 are primes, so a(13)=3. %Y A136626 Cf. A063826, A115258, A136627. %K A136626 easy,nonn %O A136626 1,1 %A A136626 _Paolo P. Lava_ and _Giorgio Balzarotti_, Jan 14 2008 %E A136626 Offset 1 per example and correction for a(32) by _Kevin Ryde_, Jul 04 2020