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 A268675 #7 Feb 11 2016 12:09:58 %S A268675 1,2,3,8,5,6,7,4,21,10,11,24,13,14,15,32,17,42,19,40,9,22,23,12,55,26, %T A268675 27,56,29,30,31,16,69,34,35,168,37,38,39,20,41,18,43,88,93,46,47,96, %U A268675 91,110,123,104,53,54,25,28,117,58,59,120,61,62,63,64,65,138,67,136,33,70,71,84,73,74,75,152,77,78,79,160 %N A268675 Self-inverse permutation of natural numbers: a(1) = 1; a(n) = A000079(A193231(A007814(n))) * A250469(a(A268674(n))). %H A268675 Antti Karttunen, <a href="/A268675/b268675.txt">Table of n, a(n) for n = 1..1914</a> %H A268675 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a> %F A268675 a(1) = 1, and for n > 1, a(n) = A000079(A193231(A007814(n))) * A250469(a(A268674(n))). %F A268675 Other identities. For all n >= 1: %F A268675 A000035(a(n)) = A000035(n). [This permutation preserves the parity of n.] %F A268675 A020639(a(n)) = A020639(n). [More generally, it preserves the smallest prime dividing n.] %F A268675 A055396(a(n)) = A055396(n). %o A268675 (Scheme, with memoization-macro definec) %o A268675 (definec (A268675 n) (if (= 1 n) 1 (* (A000079 (A193231 (A007814 n))) (A250469 (A268675 (A268674 n)))))) %Y A268675 Cf. A000079, A000265, A007814, A193231, A250469, A268674. %Y A268675 Cf. also A268385. %K A268675 nonn %O A268675 1,2 %A A268675 _Antti Karttunen_, Feb 11 2016