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 A116995 #6 Sep 16 2015 00:24:19
%S A116995 5,12,35,70,176,247,425,532,782,1247,1426,2035,2501,2752,3290,4187,
%T A116995 5192,5551,6700,7526,7957,9322,10292,11837,14065,15251,15862,17120,
%U A116995 17767,19097,24130,25676,28085,28912,33227,34126,36895,39772,41750,44807
%N A116995 Pentagonal numbers with prime indices.
%C A116995 See also: A001248 Squares of primes. A034953 Triangular numbers (A000217) with prime indices.
%F A116995 a(n) = Prime(n)*(3*Prime(n)-1)/2. a(n) = A000326(A000040(n)).
%e A116995 a(1) = Pentagonal(prime(1)) = A000326(2) = 2*(3*2-1)/2 = 5.
%e A116995 a(2) = Pentagonal(prime(2)) = A000326(3) = 3*(3*3-1)/2 = 12.
%e A116995 a(3) = Pentagonal(prime(3)) = A000326(5) = 5*(3*5-1)/2 = 35.
%t A116995 Table[Prime[n]*(3*Prime[n] - 1)/2, {n, 1, 60}] (* _Stefan Steinerberger_, Apr 04 2006 *)
%Y A116995 Cf. A000040, A000326, A001248, A034953.
%K A116995 easy,nonn
%O A116995 1,1
%A A116995 _Jonathan Vos Post_, Apr 02 2006