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 A250472 #15 Dec 13 2014 00:41:02 %S A250472 1,2,3,5,4,7,11,6,13,17,8,19,9,10,23,29,12,15,31,14,37,41,16,43,25,18, %T A250472 47,21,20,53,59,22,27,61,24,67,71,26,35,73,28,79,33,30,83,55,32,39,89, %U A250472 34,97,101,36,103,107,38,109,45,40,65,49,42,51,113,44,127,85,46,131,137,48,77,57,50,139,149,52,63,151,54,95,157,56,163,121,58,167,69,60 %N A250472 Permutation of natural numbers: a(n) = A250470(2*n - 1). %C A250472 For n > 1, a(n) tells which number is located immediately above n in the sieve of Eratosthenes (see A083140, A083221) in the same column of the sieve that contains 2n - 1. %H A250472 Antti Karttunen, <a href="/A250472/b250472.txt">Table of n, a(n) for n = 1..4096</a> %H A250472 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a> %F A250472 a(1) = 1, a(n) = A083221(A055396(2*n - 1)-1, A078898(2*n - 1)). %F A250472 a(n) = A250470(2*n - 1). %o A250472 (Scheme, two alternatives) %o A250472 (define (A250472 n) (A250470 (+ n n -1))) %o A250472 (define (A250472 n) (if (= 1 n) n (A083221bi (- (A055396 (+ n n -1)) 1) (A078898 (+ n n -1))))) ;; Code for A083221bi given in A083221. %Y A250472 Inverse: A250471. %Y A250472 Odd bisection of A250470. The other bisection: A250479. %Y A250472 Cf. A055396, A064216, A078898, A083140, A083221, A114881, A114883. %K A250472 nonn %O A250472 1,2 %A A250472 _Antti Karttunen_, Dec 06 2014