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 A171921 #3 Mar 30 2012 17:28:13 %S A171921 1,2,4,6,11,12,16,14,24,29,9,32,23,38,8,41,26,40,43,42,71,35,53,47,58, %T A171921 64,20,37,84,50,62,76,34,70,101,122,44,92,117,59,5,102,88,98,93,96, %U A171921 119,19,133,104,128,146,78,145,151,157,94,180,134,148,139,144 %N A171921 New numbers in A171922 in order of appearance. %C A171921 A171922 is fully fully characterized by this sequence. %C A171921 Does every positive number appear? Is this a permutation of the positive integers? %H A171921 Hugo van der Sanden, <a href="/A171921/b171921.txt">Table of n, a(n) for n = 1..2347</a> %Y A171921 Cf. A171922, A171926, A171927, A171930. %K A171921 nonn %O A171921 1,2 %A A171921 _Hugo van der Sanden_, Oct 23 2010