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 A253886 #5 Jan 18 2015 19:05:36 %S A253886 0,2,4,8,6,14,10,20,24,26,12,32,16,38,34,44,18,50,22,56,54,62,28,68, %T A253886 48,74,64,80,30,86,36,92,84,98,76,104,40,110,94,116,42,122,46,128,114, %U A253886 134,52,140,120,146,124,152,58,158,90,164,144,170,60,176,66,182,154,188,118,194,70,200,174,206,72,212,78,218,184,224,142,230,82 %N A253886 Permutation of even numbers: a(n) = A250469(n+1) - 1. %H A253886 Antti Karttunen, <a href="/A253886/b253886.txt">Table of n, a(n) for n = 0..5000</a> %F A253886 a(n) = A250469(n+1) - 1. %o A253886 (Scheme) (define (A253886 n) (- (A250469 (+ n 1)) 1)) %Y A253886 Cf. A250469, A253885, A249814. %K A253886 nonn %O A253886 0,2 %A A253886 _Antti Karttunen_, Jan 18 2015