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 A261221 #15 Mar 30 2017 21:58:21 %S A261221 0,1,1,1,2,2,2,2,3,4,4,4,4,5,5,5,6,6,6,6,7,7,7,7,8,9,9,9,9,10,10,10, %T A261221 10,11,11,11,12,12,12,12,13,13,13,13,14,14,14,14,14,15,15,15,15,16,16, %U A261221 16,16,17,17,17,17,17,18,18,19,19,19,19,20,20,20,20,21,21,21,21,21,22,22,22,23,24,24,24,24,25,25,25,25,26,26,26,26,26,27,27,27,28,28,28,29 %N A261221 a(n) = number of steps to reach 0 when starting from k = n and repeatedly applying the map that replaces k with k - A053610(k), where A053610(k) = the number of positive squares needed to sum to k using the greedy algorithm. %H A261221 Antti Karttunen, <a href="/A261221/b261221.txt">Table of n, a(n) for n = 0..10000</a> %F A261221 a(0) = 0; for n >= 1, a(n) = 1 + a(A260740(n)). %o A261221 (Scheme, with memoization-macro definec) %o A261221 (definec (A261221 n) (if (zero? n) n (+ 1 (A261221 (A260740 n))))) %Y A261221 Cf. A260740, A261222, A261223, A261224. %Y A261221 Cf. also A260731, A261226. %K A261221 nonn %O A261221 0,5 %A A261221 _Antti Karttunen_, Aug 12 2015