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 A175321 #5 Nov 16 2017 15:52:24 %S A175321 121625477,122333819,123043313,124851563,126163468,126613411, %T A175321 126626011,126636371,127658702,129906953,131093747,138737792, %U A175321 142368959,147338216,149348951,152446388,157519459,161172208,161352166 %N A175321 Integers greater than 120 million which cannot be represented as half-sums (averages) of two primes with indices that are primes with prime indices. %C A175321 Appears to be complete with 19 terms. If a(20) exists, it is greater than 10^9. %C A175321 Computed at the suggestion of _Jonathan Vos Post_. %F A175321 a(n)=A175320(n+1578708). %K A175321 nonn %O A175321 1,1 %A A175321 _Jason Kimberley_, Apr 04 2010