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 A256408 #17 Jan 08 2018 02:15:58 %S A256408 2,3,5,9,13,17,22,25,29,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54, %T A256408 55,56,57,58,59,60,61,62,63,64,65,66,67,68,70,81,86,89,97,100,146,153, %U A256408 154,169,196,198,249,253,300,337,340,409,411,412,414,449,587,589,610,625,958,1201,1202 %N A256408 List of successive smallest missing numbers in A166133. %C A256408 A256405 with duplicates omitted. %C A256408 See the "blog" file in A166133 for discussion. %C A256408 Records in A256405. - _Ray Chandler_, Apr 06 2015 %H A256408 N. J. A. Sloane & John Mason, <a href="/A256408/b256408.txt">Table of n, a(n) for n = 1..199</a>, first 86 terms from N. J. A. Sloane. %Y A256408 Cf. A166133, A256405, A256409. %K A256408 nonn %O A256408 1,1 %A A256408 _N. J. A. Sloane_, Apr 01 2015