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 A002648 M4910 N2105 #61 Feb 16 2025 08:32:26
%S A002648 13,109,193,433,769,1201,1453,2029,3469,3889,4801,10093,12289,13873,
%T A002648 18253,20173,21169,22189,28813,37633,43201,47629,60493,63949,65713,
%U A002648 69313,73009,76801,84673,106033,108301,112909,115249,129793,139969,142573,147853,169933
%N A002648 A variant of the cuban primes: primes p = (x^3 - y^3)/(x - y) where x = y + 2.
%C A002648 Primes p such that p = 1 + 3*m^2 for some integer m (A111051). - _Michael Somos_, Sep 15 2005
%D A002648 A. J. C. Cunningham, Binomial Factorisations, Vols. 1-9, Hodgson, London, 1923-1929; see Vol. 1, pp. 245-259.
%D A002648 N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
%D A002648 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
%H A002648 Vincenzo Librandi, <a href="/A002648/b002648.txt">Table of n, a(n) for n = 1..5000</a>
%H A002648 A. J. C. Cunningham, <a href="/A001912/a001912.pdf">Binomial Factorisations</a>, Vols. 1-9, Hodgson, London, 1923-1929. [Annotated scans of a few pages from Volumes 1 and 2]
%H A002648 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/CubanPrime.html">Cuban Prime</a>.
%H A002648 Wikipedia, <a href="http://en.wikipedia.org/wiki/Cuban_prime">Cuban prime</a>.
%F A002648 a(n) = 3*A111051(n)^2 + 1. - _Paul F. Marrero Romero_, Nov 03 2023
%e A002648 193 is a term since 193 = (9^3 - 7^3)/(9 - 7) is a prime.
%t A002648 Select[Table[3n^2+1,{n,0,700}],PrimeQ] (* _Vincenzo Librandi_, Dec 02 2011 *)
%o A002648 (PARI) {a(n)= local(m, c); if(n<1, 0, c=0; m=1; while( c<n, m++; if( isprime(m)&issquare((m-1)/3), c++)); m)} /* _Michael Somos_, Sep 15 2005 */
%o A002648 (Magma) [a: n in [0..400] | IsPrime(a) where a is 3*n^2+1]; // _Vincenzo Librandi_, Dec 02 2011
%Y A002648 Cf. A002407, A111051 (values of m).
%Y A002648 A subsequence of A007645.
%K A002648 nonn
%O A002648 1,1
%A A002648 _N. J. A. Sloane_
%E A002648 Entry revised by _N. J. A. Sloane_, Jan 29 2013