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 A239965 #24 Jul 05 2014 11:12:55 %S A239965 1,2,3,4,7,5,6,10,8,11,9,12,15,13,14,18,21,16,20,17,22,25,23,19,24,28, %T A239965 26,29,27,30,33,31,32,43,34,37,35,36,40,44,38,45,39,46,49,47,41,48,52, %U A239965 50,42,51,53,56,54,60,55,57,64,58,59,74,62,65,61,63,71 %N A239965 Where the n-th nonprime occurs in the nonprime EKG sequence A240024. %C A239965 A240024(a(n)) = A018252(n); %C A239965 a permutation of the natural numbers with inverse A238862: a(A238862(n))=A238862(a(n))=n. %H A239965 Reinhard Zumkeller, <a href="/A239965/b239965.txt">Table of n, a(n) for n = 1..10000</a> %H A239965 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a> %o A239965 (Haskell) %o A239965 import Data.List (elemIndex); import Data.Maybe (fromJust) %o A239965 a239965 = (+ 1) . fromJust . (`elemIndex` a240024_list) . a018252 %Y A239965 Cf. A239943 (fixed points). %K A239965 nonn %O A239965 1,2 %A A239965 _Reinhard Zumkeller_, Apr 30 2014