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 A031886 #10 Nov 15 2019 06:28:14 %S A031886 3,9,21,33,63,69,75,111,129,159,189,201,219,231,237,285,303,327,357, %T A031886 429,483,537,579,615,639,651,723,735,741,777,801,819,927,933,957,975, %U A031886 993,1053,1101,1179,1197,1245,1281,1365,1455,1491,1497,1563 %N A031886 Lucky numbers with size of gaps equal to 4 (lower terms). %C A031886 This is to lucky numbers (A000959) as smaller member p of cousin prime pairs (A023200) is to primes (A000040). - _Jonathan Vos Post_, May 08 2007 %H A031886 Amiram Eldar, <a href="/A031886/b031886.txt">Table of n, a(n) for n = 1..10000</a> %Y A031886 Cf. A000959. %Y A031886 Cf. A000040, A023200. %K A031886 nonn %O A031886 1,1 %A A031886 _Patrick De Geest_