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 A255072 #10 Feb 17 2015 00:11:25 %S A255072 0,1,1,2,2,2,3,4,4,4,4,5,5,5,6,7,7,7,7,8,8,8,8,9,9,9,9,10,10,10,11,12, %T A255072 12,12,12,13,13,13,13,14,14,14,14,14,15,15,15,16,16,16,16,17,17,17,17, %U A255072 18,18,18,18,19,19,19,20,21,21,21,21,22,22,22,22,23,23,23,23,23,24,24,24,25 %N A255072 Number of steps to reach 0 starting with n and using the iterated process: x -> x - (number of runs in binary representation of x). %H A255072 Antti Karttunen, <a href="/A255072/b255072.txt">Table of n, a(n) for n = 0..8192</a> %F A255072 a(0) = 0; for n >= 1, a(n) = 1 + a(A236840(n)) = 1 + a(n - A005811(n)). %F A255072 Other identities. For all n >= 0: %F A255072 a(A255053(n)) = a(A255055(n)) = n. %F A255072 a(A255056(n)) = n. [This sequence works also as an inverse function for number-of-runs beanstalk A255056.] %o A255072 (Scheme, with memoization-macro definec) %o A255072 (definec (A255072 n) (if (zero? n) 0 (+ 1 (A255072 (A236840 n))))) %Y A255072 Cf. A255053 (least inverse), A255055 (greatest inverse), A255054 (run lengths). %Y A255072 Cf. A005811, A236840, A255071, A255056. %Y A255072 Cf. A255061 & A255062 (values at points (2^n)-2 and (2^n)-1). %Y A255072 Analogous sequences: A071542, A219642, A219652 %K A255072 nonn %O A255072 0,4 %A A255072 _Antti Karttunen_, Feb 14 2015