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 A228451 #24 Mar 28 2019 14:54:05 %S A228451 0,1,1,4,1,6,4,11,1,10,6,17,4,17,11,26,1,18,10,29,6,27,17,40,4,29,17, %T A228451 44,11,40,26,57,1,34,18,53,10,47,29,68,6,47,27,70,17,62,40,87,4,53,29, %U A228451 80,17,70,44,99,11,68,40,99,26,87,57,120,1,66,34,101,18,87,53,124,10,83,47,122,29,106,68 %N A228451 Recurrence: a(2n) = a(n), a(2n+1) = a(n) + 2n + 1, with a(0) = 0, a(1) = 1. %C A228451 Unique values are 0,1,4,6,10,11,17,18,26,27,29,34,40,47,53,57,62,68... %H A228451 Antti Karttunen, <a href="/A228451/b228451.txt">Table of n, a(n) for n = 0..16384</a> %H A228451 Antti Karttunen, <a href="/A228451/a228451.txt">Data supplement: n, a(n) computed for n = 0..65536</a> %F A228451 For m>0, a(2^m+1) = 2^m+2, a(2^m+2) = 2^(m-1)+2, a(2^m+3) = 3*2^m+5, a(2^m+2^(m-1)) = 4, a(2^m-1) = 2^(m+1) - m - 2. %o A228451 (PARI) a(n)=if(n<2,n==1,if(n%2,n+a(n-1),a(n/2))) %Y A228451 Cf. A030067, A000265, A000120. %K A228451 nonn,look %O A228451 0,4 %A A228451 _Ralf Stephan_, Oct 27 2013 %E A228451 Name corrected by _Gionata Neri_, Mar 27 2019