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 A175319 #4 Oct 13 2012 00:22:37 %S A175319 5,8,11,18,21,31,32,35,45,59,66,69,79,92,93,95,105,119,127,141,144, %T A175319 153,154,168,171,179,181,195,202,218,221,228,229,231,245,255,277,279, %U A175319 302,304,305,315,329,331,354,357,360,363,370,381,384,389,418,431,438,444 %N A175319 Half-sums (averages) of two primes with indices that are primes with prime indices. %C A175319 The complement is A175320 which appears to be finite. %C A175319 Computed at the suggestion of _Jonathan Vos Post_. %F A175319 (A038580(i) + A038580(j))/2 %Y A175319 Cf. A174681 %K A175319 easy,nonn %O A175319 1,1 %A A175319 _Jason Kimberley_, Apr 04 2010