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 A256563 #7 Apr 14 2015 09:59:31 %S A256563 3,7,12,11,15,14,17,24,29,28,36,35,34,31,30,47,50,52,56,58,59,63,66, %T A256563 25,77,74,92,89,102,101,109,107,106,105,83,116,128,125,124,143,142, %U A256563 141,135,131,147,154,155,156,103,171,99,96,95,145,189,259,178,177 %N A256563 Indices of semiprimes in A166133. %H A256563 Reinhard Zumkeller and Ray Chandler, <a href="/A256563/b256563.txt">Table of n, a(n) for n = 1..10000</a> (first 1000 terms from Reinhard Zumkeller) %F A256563 a(n) = A255833(A001358(n)). - _Ray Chandler_, Apr 14 2015 %o A256563 (Haskell) %o A256563 a256563 = (+ 1) . fromJust . (`elemIndex` a166133_list) . a001358 %Y A256563 Cf. A166133, A256561, A255833, A001358. %K A256563 nonn %O A256563 1,1 %A A256563 _Reinhard Zumkeller_, Apr 02 2015