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 A089682 #37 Feb 22 2025 15:48:46
%S A089682 2,11,47,107,191,431,587,971,1451,2027,2351,2699,3467,4799,5807,6911,
%T A089682 7499,8111,8747,10091,10799,14699,15551,16427,17327,18251,25391,27647,
%U A089682 36299,41771,44651,55487,57131,62207,67499,71147,74891,80687,92927,99371,103787,106031
%N A089682 Primes of the form 3*m^2 - 1.
%C A089682 431 and 27647 also have the form 2*m^3-1 (431 = 3*12^2-1 = 2*6^3-1 and 27647 = 3*96^2-1 = 2*24^3-1). [Howard Berman (howard_berman(AT)hotmail.com), May 09 2009]
%C A089682 Or, primes p such that 3*(p+1) is a square. [_Vincenzo Librandi_, Nov 18 2010]
%C A089682 Obviously m must be either 1 or an even number. So this consists of 1 together with primes of the form 12*u^2 - 1. - _N. J. A. Sloane_, Aug 09 2019
%D A089682 M. Cerasoli, F. Eugeni, and M. Protasi, Elementi di Matematica Discreta, Bologna 1988.
%D A089682 Emanuele Munarini and Norma Zagaglia Salvi, Matematica Discreta, UTET, CittaStudiEdizioni, Milano 1997.
%H A089682 Vincenzo Librandi, <a href="/A089682/b089682.txt">Table of n, a(n) for n = 1..1000</a>
%F A089682 a(n) = A080663(A089681(n)). - _Elmo R. Oliveira_, Feb 22 2025
%t A089682 Select[Table[3 n^2 - 1, {n, 0, 2000}], PrimeQ] (* _Vincenzo Librandi_, Jul 16 2012 *)
%o A089682 (Magma) [a: n in [0..200] | IsPrime(a) where a is 3*n^2-1]; // _Vincenzo Librandi_, Jul 16 2012
%Y A089682 Primes in A080663.
%Y A089682 Cf. A089681.
%K A089682 nonn,easy
%O A089682 1,1
%A A089682 _Giovanni Teofilatto_, Jan 05 2004
%E A089682 More terms from _Rick L. Shepherd_, May 18 2005