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 A160862 #4 Mar 30 2012 17:35:07 %S A160862 1,8,12,8,11,16,5,12,11,1,9,12,2,13,10,8,12,12,4,8,11,13,3,8,10,12,13, %T A160862 3,9,13,2,3,12,11,12,15,8,9,13,8,13,8,11,4,14,11,11,13,4,11,10,10,12, %U A160862 14,12 %N A160862 a(n) = length of period of transformation sum-digit-square: given a number m(k) define m(k+1) to be the sum of the squares of the decimal digits of m(k) and iterate until m(s) is found such that m(s)=m(k) with k<s. Numbers repeat periodically with a period of length a(n). %D A160862 C. Suriano, Miniature Matematiche, unpublished, 2009, section 30 %e A160862 a(1)=1 since 1^2=1; a(2)=8 since the period contains 8 numbers: 4,16,37,58,89,145,42,20 the following being 4 again. %e A160862 a(5)=11 since the sequence runs as follows: %e A160862 25,29, 85, 89, 145, 42, 20, 4, 16, 37, 58 the next term being 89 that is already there. %Y A160862 Cf. A152077. %K A160862 nonn,base %O A160862 1,2 %A A160862 _Carmine Suriano_, May 29 2009