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 A248918 #5 Oct 20 2014 14:44:35 %S A248918 1,2,3,4,5,7,6,8,9,31,10,11,12,27,28,14,16,63,17,18,19,20,32,21,22,23, %T A248918 127,24,25,26,29,115,30,33,34,35,36,37,38,39,40,111,41,255,42,43,44, %U A248918 45,46,47,48,49,50,51,52,53,54,56,58,59,60,61,62,64,66,67 %N A248918 a(n) = index of (n+1)-th prime power in A247665. %o A248918 (Haskell) %o A248918 import Data.List (elemIndex); import Data.Maybe (fromJust) %o A248918 a248918 = (+ 1) . fromJust . (`elemIndex` a247665_list) . a000961 . (+ 1) %Y A248918 Cf. A248387 (subsequence), A000961. %K A248918 nonn %O A248918 1,2 %A A248918 _Reinhard Zumkeller_, Oct 16 2014