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 A121508 #3 Oct 19 2017 03:15:03 %S A121508 562,1064,1188,1308,1336,1380,1420,1490,1604,1690,1692,1772,1816,1898, %T A121508 2008,2122,2152,2172,2362,2542,2630,2652,2676,2678,2856,2930,2950, %U A121508 2974,3124,3162,3202,3278,3286,3332,3350,3360,3596,3712,3750,3850,3938,3944 %N A121508 Conjectured list of numbers whose aliquot sequence eventually reaches a cycle of length two or more, but which are not themselves part of the cycle. %Y A121508 Cf. A121507. %K A121508 nonn %O A121508 1,1 %A A121508 _Joshua Zucker_, Aug 04 2006 %E A121508 Edited by _Don Reble_, Aug 15 2006