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 A237704 #15 Aug 18 2015 04:52:19 %S A237704 2,6,12,30,32,40,42,72,90,132,152,192,210,240,312,342,408,420,462,480, %T A237704 552,560,592,672,702,792,870,880,888,912,930,1122,1152,1260,1272,1320, %U A237704 1332,1560,1584,1722,1752,1792,1980,2352,2520,2550,2652,2712,2862,2952,2970,3192,3560,3640,4032 %N A237704 Numbers n for which the fundamental solution of Pell's equation x^2 - n*y^2 = 1 has both x and y prime. %H A237704 Ray Chandler, <a href="/A237704/b237704.txt">Table of n, a(n) for n = 1..716</a> %H A237704 Wikipedia, <a href="https://en.wikipedia.org/wiki/Pell%27s_equation">Pell's equation</a> %e A237704 Pell's equation x^2 - 2*y^2 = 1 and its fundamental solution is (x,y) = (3,2) which are both primes, so a(1) = 2. %e A237704 (x,y) = (5,2) satisfies x^2 - 6*y^2 = 1, so a(2) = 6. %e A237704 (x,y) = (7,2) satisfies x^2 - 12*y^2 = 1, so a(3) = 12. %e A237704 Pell's equation x^2 - 2088*y^2 = 1 and (x,y) = (19603, 429), 19603 is prime, 429 = 3 * 11 * 13 is not, so 2088 is not included. %e A237704 Pell's equation x^2 - 2000*y^2 = 1 and (x,y) = (930249, 20801), 930249 = 3^2 * 41 * 2521 and 20801 = 11 * 31 * 61 are not primes, so 2000 is not included. %Y A237704 Cf. A000037, A033313, A033317. %K A237704 nonn %O A237704 1,1 %A A237704 _Jani Melik_, Feb 11 2014 %E A237704 420 inserted into the sequence by _Colin Barker_, Feb 12 2014