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 A219636 #8 Nov 25 2012 23:46:43 %S A219636 0,1,3,4,5,6,8,9,11,12,13,14,16,17,18,19,21,22,24,25,26,27,29,30,32, %T A219636 33,34,35,37,38,39,40,42,43,45,46,47,48,50,51,52,53,55,56,58,59,60,61, %U A219636 63,64,66,67,68,69,71,72,73,74,76,77,79,80,81,82,84,85,87 %N A219636 Complement of A035336. %C A219636 This gives positions of those numbers in A219641 that occur twice, i.e. A219637. %H A219636 A. Karttunen, <a href="/A219636/b219636.txt">Table of n, a(n) for n = 1..10000</a> %Y A219636 Cf. A035336, A219637. %K A219636 nonn %O A219636 1,3 %A A219636 _Antti Karttunen_, Nov 24 2012