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 A283481 #8 Mar 19 2017 01:09:49 %S A283481 1,2,5,9,11,12,17,19,22,25,26,27,33,35,37,38,40,43,46,47,48,50,51,55, %T A283481 56,57,58,65,67,69,72,74,77,79,80,82,83,87,89,90,92,93,97,100,101,102, %U A283481 107,110,111,112,117,118,119,120,121,129,131,133,135,136,138,140,143,145,148,150,151,153,154,158,160,163,165,166,168,169 %N A283481 Positions of odd terms in A004001. %H A283481 Antti Karttunen, <a href="/A283481/b283481.txt">Table of n, a(n) for n = 1..8121</a> %F A283481 Other identities. For all n >= 1: %F A283481 A283480(a(n)) = n. %t A283481 a[n_] := a[n] = If[n <= 2, 1, a[a[n - 1]] + a[n - a[n - 1]]]; Select[Range@ 169, OddQ@ a[#] &] (* _Michael De Vlieger_, Mar 18 2017, after _Robert G. Wilson v_ at A004001 *) %o A283481 (Scheme, with _Antti Karttunen_'s IntSeq-library) %o A283481 (define A283481 (NONZERO-POS 1 1 A095901)) %Y A283481 Cf. A283482 (complement), A283480 (a left inverse). %Y A283481 Positions of ones in A095901. %Y A283481 Cf. A004001. %K A283481 nonn %O A283481 1,2 %A A283481 _Antti Karttunen_, Mar 18 2017