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 A174521 #6 May 13 2017 17:01:01
%S A174521 193,673,1873,2207,2833,4391,3023,8209,5903,8999,6047,9643,7537,19843,
%T A174521 10273,29399,11953,12433,20879,35999,36241,23761,23831,24907,20353,
%U A174521 32401,33403,22367,34129,57367,49123,74311,51197,40037,42773,71399
%N A174521 Primes that are the sum of all composite numbers in-between prime numbers p(n) and p(n+2).
%C A174521 20+21+22+24+25+26+27+28=193,..
%H A174521 Harvey P. Dale, <a href="/A174521/b174521.txt">Table of n, a(n) for n = 1..2000</a>
%t A174521 f[n_,x_]:=n*x+x*(x+1)/2;Select[Table[f[Prime[n],Prime[n+2]-Prime[n]-1]-Prime[n+1],{n,6!}],PrimeQ[ # ]&]
%t A174521 Select[Table[Total[Select[Range[Prime[n],Prime[n+2]],CompositeQ]],{n,1000}],PrimeQ] (* _Harvey P. Dale_, May 13 2017 *)
%Y A174521 Cf. A034962, A054265, A174518, A174519, A174520
%K A174521 nonn
%O A174521 1,1
%A A174521 _Vladimir Joseph Stephan Orlovsky_, Mar 21 2010