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 A031885 #8 May 04 2020 02:22:47 %S A031885 3,7,21,87,151,63,801,511,189,957,925,769,2877,1639,1087,3843,5803, %T A031885 4929,8757,10723,9883,24117,9613,28293,25737,3559,26997,35799,44863, %U A031885 52039,64785,23269,50845,51543,264145,155905,238131,178831,143389,400671,223177,181665 %N A031885 Lucky numbers with smallest increasing gaps (upper terms). %Y A031885 Cf. A000959, A031884. %K A031885 nonn %O A031885 1,1 %A A031885 _Patrick De Geest_ %E A031885 a(27) corrected and more terms from _Sean A. Irvine_, May 03 2020