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 A065396 #6 Dec 16 2017 11:23:11
%S A065396 3,5,11,13,17,19,23,29,31,37,41,43,47,53,59,67,71,73,79,83,89,97,101,
%T A065396 103,107,109,113,127,131,137,139,149,151,157,163,167,173,179,181,191,
%U A065396 193,197,199,223,227,229,233,239,241,251,257,263,269,271,277,281,283
%N A065396 Primes of the form p + k*(k+1) / 2, p prime and k > 0.
%C A065396 a(2) = 11 = 5 + 3*(3+1) / 2.
%H A065396 Harvey P. Dale, <a href="/A065396/b065396.txt">Table of n, a(n) for n = 1..1000</a>
%t A065396 Module[{upto=300,trs},trs=Accumulate[Range[(Sqrt[1+8upto]-1)/2]];Select[ Flatten[ Table[p+trs,{p,Prime[Range[PrimePi[upto]]]}]],PrimeQ[#] && #<=upto&]]//Union (* _Harvey P. Dale_, Dec 16 2017 *)
%Y A065396 A000040, A000217, A065376, A065397.
%K A065396 nonn
%O A065396 1,1
%A A065396 _Reinhard Zumkeller_, Nov 05 2001