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 A249595 #4 Nov 04 2014 05:57:20 %S A249595 1,3,5,6,8,9,10,13,15,16,20,21,24,25,26,28,29,31,33,35,36,39,40,43,44, %T A249595 46,48,49,52,56,57,59,60,62,63,66,67,69,70,73,76,77,79,82,83,85,86,88, %U A249595 91,92,93,95,96,98,99,101,103,104,106,107,110,112,114,115 %N A249595 Positions of nonprimes in A249054. %C A249595 A249054(a(n)) = A018252(n); sequence is strictly increasing, i.e. all nonprimes occur in A249054 in natural order, see also A249594. %H A249595 Reinhard Zumkeller, <a href="/A249595/b249595.txt">Table of n, a(n) for n = 1..10000</a> %o A249595 (Haskell) %o A249595 import Data.List (elemIndex); import Data.Maybe (fromJust) %o A249595 a249595 = (+ 1) . fromJust . (`elemIndex` a249054_list) . a018252 %Y A249595 Cf. A018252, A026233, A049084, A239968, A249054, A249594 (complement). %K A249595 nonn %O A249595 1,2 %A A249595 _Reinhard Zumkeller_, Nov 03 2014