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 A269355 #12 Mar 03 2016 22:48:36 %S A269355 1,2,3,4,5,6,7,8,23,10,11,12,13,14,15,16,9,18,17,20,31,22,25,24,21,26, %T A269355 27,28,19,30,29,32,49,34,71,36,37,38,39,40,41,42,43,44,107,46,47,48, %U A269355 119,50,51,52,35,54,89,56,101,58,53,60,61,62,63,64,115,66,67,68,173,70,55,72,33,74,75,76,131,78,77,80,167 %N A269355 Permutation of natural numbers: a(n) = A269380(A250469(n)). %H A269355 Antti Karttunen, <a href="/A269355/b269355.txt">Table of n, a(n) for n = 1..10000</a> %H A269355 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a> %F A269355 a(n) = A269380(A250469(n)). %F A269355 Other identities. For all n >= 1: %F A269355 a(2n) = 2n. [Fixes the even numbers.] %e A269355 For n=9 we first find what number is below 9 in square array A083221, which is 25, then we find what number is above 25 in square array A255127, which is 23, thus a(9) = 23. %o A269355 (Scheme) (define (A269355 n) (A269380 (A250469 n))) %Y A269355 Inverse: A269356. %Y A269355 Cf. A250469, A269380. %Y A269355 Cf. also arrays A083221 & A255127. %Y A269355 More recursed variant: A269357. Cf. also permutations A266645, A255407, A269171. %K A269355 nonn %O A269355 1,2 %A A269355 _Antti Karttunen_, Mar 03 2016