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 A273671 #9 May 29 2016 08:01:01 %S A273671 1,8,2,27,54,24,3,64,250,375,192,108,135,40,4,125,686,96,1029,1372, %T A273671 160,1715,500,320,875,16000,448,189,3456,56,5,216,1458,3993,3000,5324, %U A273671 10985,8640,2916,3645,12096,281216,9317,7000,170368,5103,1080,750,3087,352,3430,3773,416,4116,1125,576,1500,1625,704,270,297,72,6,343 %N A273671 Permutation of natural numbers: a(n) = A270436(A007305(n+1)) * A270437(A047679(n-1)). %C A273671 Permutation of natural numbers induced by looking up the position of A007305(n+1)/A047679(n-1) [each fraction in the full Stern-Brocot tree] in the set of positive rationals as ordered by A270418(n)/A270419(n). %H A273671 Antti Karttunen, <a href="/A273671/b273671.txt">Table of n, a(n) for n = 1..8192</a> %H A273671 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a> %F A273671 a(n) = A270436(A007305(n+1)) * A270437(A047679(n-1)). %o A273671 (Scheme) (define (A273671 n) (* (A270436 (A007305 (+ 1 n))) (A270437 (A047679 (- n 1))))) %Y A273671 Inverse: A273672. %Y A273671 Cf. A007305, A047679, A270418, A270419, A270436, A270437. %K A273671 nonn,look %O A273671 1,2 %A A273671 _Antti Karttunen_, May 27 2016