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 A264993 #8 Dec 13 2015 07:48:42 %S A264993 0,1,3,2,4,5,11,7,12,19,15,6,8,18,14,10,16,17,13,9,20,21,43,27,44,75, %T A264993 59,23,28,71,55,39,48,67,51,35,76,83,47,31,60,79,63,22,24,70,54,38,32, %U A264993 66,50,34,72,82,46,30,56,78,62,26,40,74,58,42,64,65,49,33,68,81,45,29,52,77,61,25,36,73,57,41,80,69 %N A264993 Self-inverse permutation of nonnegative integers: a(n) = A264994(3*n)/3. %H A264993 Antti Karttunen, <a href="/A264993/b264993.txt">Table of n, a(n) for n = 0..21845</a> %H A264993 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a> %o A264993 (Scheme) (define (A264993 n) (/ (A264994 (* 3 n)) 3)) %Y A264993 Cf. A264994. %Y A264993 Cf. also A246200, A265335. %K A264993 nonn,base %O A264993 0,3 %A A264993 _Antti Karttunen_, Dec 07 2015