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 A270425 #12 Mar 25 2016 23:01:42 %S A270425 1,2,3,4,7,6,5,8,9,14,19,12,13,10,29,16,25,18,11,28,15,38,23,24,17,26, %T A270425 27,20,55,58,37,32,41,50,73,36,31,22,39,56,67,30,49,76,63,46,117,48, %U A270425 59,34,75,52,79,54,77,40,33,110,129,116,47,74,21,64,155,82,57,100,93,146,221,72,35,62,51,44,71,78,53,112,113,134,227,60 %N A270425 Permutation of natural numbers: a(1) = 1, a(2n) = 2*a(n), a(2n+1) = 1 + 2*a(A265354(n)). %H A270425 Antti Karttunen, <a href="/A270425/b270425.txt">Table of n, a(n) for n = 1..10000</a> %H A270425 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a> %F A270425 a(1) = 1, a(2n) = 2*a(n), a(2n+1) = 1 + 2*a(A265354(n)). %o A270425 (Scheme, with memoization-macro definec) %o A270425 (definec (A270425 n) (cond ((= 1 n) n) ((even? n) (* 2 (A270425 (/ n 2)))) (else (+ 1 (* 2 (A270425 (A265354 (/ (- n 1) 2)))))))) %Y A270425 Inverse: A270426. %Y A270425 Cf. A265354. %K A270425 nonn,base,less %O A270425 1,2 %A A270425 _Antti Karttunen_, Mar 17 2016