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 A269394 #4 Mar 07 2016 12:30:28 %S A269394 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 A269394 27,28,29,30,31,32,33,34,35,36,49,38,39,40,41,42,43,44,37,46,47,48,45, %U A269394 50,51,52,53,54,55,56,57,58,59,60,97,62,63,64,65,66,67,68,69,70,71,72,61,98,99,76,77,78,79,80,73,82,83,84,81 %N A269394 Permutation of natural numbers: a(n) = A269172(3*n) / 3. %C A269394 The first non-fixed term is a(37)=49. %H A269394 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a> %F A269394 a(n) = A269172(3*n) / 3. %o A269394 (Scheme) (define (A269394 n) (/ (A269172 (* 3 n)) 3)) %Y A269394 Inverse: A269393. %Y A269394 Cf. A269172, A269396. %K A269394 nonn %O A269394 1,2 %A A269394 _Antti Karttunen_, Mar 03 2016