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 A220968 #7 Jul 13 2013 12:04:35 %S A220968 1,5,6,9,11,13,15,16,17,20,21,23,25,27,28,29,31,33,34,36,38,39,40,42, %T A220968 44,45,47,49,50,52,54,55,56,58,60,61,63,65,67,68,70,71,73,74,75,76,77, %U A220968 79,81,82,85,86,87,89,90,92,93,94,96,97,98,100,101,104,105 %N A220968 Positions in A030229 where odd terms occur. %C A220968 A030229(a(n)) mod 2 = 1; A020639(A030229(a(n))) > 2. %H A220968 Reinhard Zumkeller, <a href="/A220968/b220968.txt">Table of n, a(n) for n = 1..10000</a> %o A220968 (Haskell) %o A220968 import Data.List (findIndices) %o A220968 a220968 n = a220968_list !! (n-1) %o A220968 a220968_list = map (+ 1) $ findIndices odd a030229_list %Y A220968 Cf. A220969 (complement). %K A220968 nonn %O A220968 1,2 %A A220968 _Reinhard Zumkeller_, Dec 27 2012