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 A056529 #3 Mar 30 2012 18:51:27 %S A056529 0,3,1,2,2,1,1,2,0,1,3,1,0,1,1,0,3,1,2,3,1,1,1,2,1,3,2,3,1,1,1,2,2,1, %T A056529 2,2,3,1,1,2,1,2,2,3,1,2,1,1,2,2,1,1,3,2,2,1,2,1,1,1,1,3,3,3,1,2,2,1, %U A056529 2,1,2,2,3,2,2,2,2,2,1,2,2,3,2,2,1,2,3,2,3,1,3,2,3,2,1,2,2,3,2,1,3,1,1,1,1 %N A056529 Number of iterations of sum of digits of square to reach 1, 9, 13 or 16. %e A056529 a(2)=3 because successive iterations give 2 -> 4 -> 7 -> 13 -> 16 -> 13 etc. %Y A056529 Cf. A004159 for sum of digits of square, A056528 for two iterations, A056020 where iteration settles to 1, A056020 where iteration settles to 9, A056527 where iteration settles to 13 and 16. %K A056529 base,easy,nonn %O A056529 1,2 %A A056529 _Henry Bottomley_, Jun 19 2000