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 A249041 #12 May 02 2019 09:50:57 %S A249041 1,1,1,2,3,4,4,5,5,5,5,5,6,6,6,7,8,8,9,10,11,12,13,13,14,15,16,16,17, %T A249041 17,17,18,19,19,20,20,20,20,21,21,21,21,21,21,21,22,22,22,22,22,23,23, %U A249041 23,24,25,25,26,26,26,26,27,27,27,28,29,29,30,31,32,32,33,33,33,34,35,35,36 %N A249041 Number of odd terms in first n terms of A249039. %H A249041 Reinhard Zumkeller, <a href="/A249041/b249041.txt">Table of n, a(n) for n = 1..10000</a> %H A249041 Rémy Sigrist, <a href="/A249041/a249041.png">Colored scatterplot of (a(n-1-a(n-1))/n, a(a(n-1))/n) for n <= 500000000</a> (where the hue is function of n) %F A249041 For n > 2: a(n) = a(n-1) + A249039(n) mod 2. - _Reinhard Zumkeller_, Nov 11 2014 %F A249041 a(n) = n - a(a(n-1)) - a(n-1-a(n-1)) with a(1) = a(2) = 1. - _Altug Alkan_, May 01 2019 %p A249041 See A249039. %o A249041 (Haskell) %o A249041 a249041 n = a249041_list !! (n-1) %o A249041 a249041_list = tail $ scanl (\i j -> i + mod j 2) 0 a249039_list %o A249041 -- _Reinhard Zumkeller_, Nov 11 2014 %Y A249041 Cf. A249039, A249040, A287422. %K A249041 nonn %O A249041 1,4 %A A249041 _N. J. A. Sloane_, Oct 26 2014