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 A231988 #5 Nov 19 2013 13:20:40 %S A231988 7,29,67,191,277,947,1129,2557,5779,8647,13367,14029,16111,22367, %T A231988 24977,31627,36857,47279,64621,87991,93097,96581,98347,109279,126757, %U A231988 163307,239087,282377,329267,342379,352381,372817,411779,448879,468029,471907,491537,519691,531997 %N A231988 Primes of the form triangular(p) + 1, where p is a prime. %C A231988 Triangular(p) = p*(p+1)/2. %F A231988 a(n) = A000217(A231847(n))+1. %t A231988 t = Select[Prime[Range[300]], PrimeQ[# (# + 1)/2 + 1] &]; t*(t + 1)/2 + 1 (* _T. D. Noe_, Nov 19 2013 *) %Y A231988 Cf. A000040, A000217, A231847. %K A231988 nonn %O A231988 1,1 %A A231988 _Alex Ratushnyak_, Nov 16 2013