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 A264978 #9 Dec 06 2015 21:13:06 %S A264978 0,1,2,3,8,5,6,7,4,9,10,17,24,26,14,15,23,11,18,29,20,21,25,16,12,22, %T A264978 13,27,28,19,30,71,44,51,62,35,72,89,53,78,80,41,42,68,32,45,86,59,69, %U A264978 77,50,33,65,38,54,83,56,87,74,47,60,61,34,63,88,52,75,79,43,48,70,31,36,85,58,66,76,49,39,67,40,81 %N A264978 Self-inverse permutation of nonnegative integers: a(n) = A263273(8*n)/8. %C A264978 Note that n=13 is the first point where this involution does not preserve the parity as a(13) = 26. %H A264978 Antti Karttunen, <a href="/A264978/b264978.txt">Table of n, a(n) for n = 0..7381</a> %H A264978 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a> %F A264978 a(n) = A263273(8*n)/8. %F A264978 a(n) = A263272(4*n)/4. %F A264978 a(n) = A264974(2*n)/2. %F A264978 Other identities. For all n >= 0: %F A264978 a(3*n) = 3*a(n). %o A264978 (Scheme, three different variants) %o A264978 (define (A264978 n) (/ (A263273 (* 8 n)) 8)) %o A264978 (define (A264978 n) (/ (A263272 (* 4 n)) 4)) %o A264978 (define (A264978 n) (/ (A264974 (* 2 n)) 2)) %Y A264978 Cf. A263273, A263272, A264974. %K A264978 nonn %O A264978 0,3 %A A264978 _Antti Karttunen_, Dec 06 2015