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 A256561 #7 Apr 14 2015 09:56:38 %S A256561 2,4,8,6,10,16,21,19,23,40,38,32,42,44,48,54,60,62,68,80,78,72,91,111, %T A256561 114,88,86,120,118,130,137,133,150,152,168,162,97,192,188,182,176,186, %U A256561 160,215,280,291,122,226,222,220,240,263,275,300,245,277,329,257 %N A256561 Indices of primes in A166133. %H A256561 Reinhard Zumkeller and Ray Chandler, <a href="/A256561/b256561.txt">Table of n, a(n) for n = 1..10000</a> (first 1000 terms from Reinhard Zumkeller) %F A256561 a(n) = A255833(A000040(n)). - _Ray Chandler_, Apr 14 2015 %o A256561 (Haskell) %o A256561 a256561 = (+ 1) . fromJust . (`elemIndex` a166133_list) . a000040 %Y A256561 Cf. A166133, A256563, A255833, A000040. %K A256561 nonn %O A256561 1,1 %A A256561 _Reinhard Zumkeller_, Apr 02 2015