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 A031883 #14 Jul 13 2015 22:38:54
%S A031883 2,4,2,4,2,6,4,6,2,4,6,6,2,12,4,2,4,2,4,8,6,6,6,6,4,12,2,4,2,6,10,8,4,
%T A031883 6,2,18,4,2,6,4,6,8,4,8,4,2,4,18,2,6,6,10,2,4,8,6,4,12,2,6,4,8,10,8,4,
%U A031883 6,18,6,2,6,10,6,6,6,2,4,18,12,12,2,6,4,2,6,16,6,2,10,6,2,4,12,6,18,2,4,8
%N A031883 First differences of lucky numbers.
%C A031883 a(n) = A254967(n,n-1). - _Reinhard Zumkeller_, Feb 11 2015
%H A031883 T. D. Noe, <a href="/A031883/b031883.txt">Table of n, a(n) for n=1..10000</a>
%t A031883 lst = Range[1, 600, 2]; i = 2; While[ i <= (len = Length@lst) && (k = lst[[i]]) <= len, lst = Drop[lst, {k, len, k}]; i++ ]; Rest@lst - Most@lst (* _Robert G. Wilson v_, May 12 2006 *)
%o A031883 (Haskell)
%o A031883 a031883 n = a031883_list !! (n-1)
%o A031883 a031883_list = zipWith (-) (tail a000959_list) a000959_list
%o A031883 -- _Reinhard Zumkeller_, Feb 11 2015
%Y A031883 Cf. A000959.
%Y A031883 Cf. A254967.
%K A031883 nonn,easy
%O A031883 1,1
%A A031883 _Patrick De Geest_