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 A322421 #9 Dec 08 2018 11:38:58
%S A322421 5,41,197,44683,360979,3619807,5353841,25106701,47525059,159781073,
%T A322421 188024357,243458497,445838927,1015334371,2018174117,2079737563,
%U A322421 4925466041,5294877781,6383922529,6531129499,6680974507,7635495793
%N A322421 Primes of the form A322420(k) or the sum of the first k*(k+1) primes.
%H A322421 Ray Chandler, <a href="/A322421/b322421.txt">Table of n, a(n) for n = 1..1000</a>
%F A322421 a(n) = A007504(A002378(A322422(n))) = A322420(A322422(n)).
%t A322421 f[n_] := Sum[Prime[k], {k, n}]; Select[
%t A322421 Table[f[n*(n + 1)], {n, 0, 240}], PrimeQ]
%Y A322421 Cf. A002378, A007504, A322420, A322422.
%K A322421 nonn
%O A322421 1,1
%A A322421 _Ray Chandler_, Dec 07 2018