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 A269393 #6 Mar 03 2016 22:51:53 %S A269393 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26, %T A269393 27,28,29,30,31,32,33,34,35,36,45,38,39,40,41,42,43,44,49,46,47,48,37, %U A269393 50,51,52,53,54,55,56,57,58,59,60,73,62,63,64,65,66,67,68,69,70,71,72,81,90,91,76,77,78,79,80,85 %N A269393 Permutation of natural numbers: a(n) = A269171(3*n) / 3. %C A269393 The first non-fixed term is a(37)=45. %H A269393 Antti Karttunen, <a href="/A269393/b269393.txt">Table of n, a(n) for n = 1..8192</a> %H A269393 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a> %F A269393 a(n) = A269171(3*n) / 3. %o A269393 (Scheme) (define (A269393 n) (/ (A269171 (* 3 n)) 3)) %Y A269393 Inverse: A269394. %Y A269393 Cf. A269171, A269395. %K A269393 nonn %O A269393 1,2 %A A269393 _Antti Karttunen_, Mar 03 2016