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 A325089 #12 Apr 12 2019 18:54:51 %S A325089 601,769,2281,2521,2689,3001,5569,5641,5881,6121,6361,6529,6841,7489, %T A325089 8209,8521,9649,9721,11329,12049,12289,12601,13009,14281,14929,15241, %U A325089 16369,17401,17881,18289,19009,19489,19801,20929,21169,21481,21649,21961,22129,22369 %N A325089 Prime numbers congruent to 49 or 121 modulo 240 representable by x^2 + 150*y^2. %C A325089 Brink showed that prime numbers congruent to 49 or 121 modulo 240 are representable by exactly one of the quadratic forms x^2 + 150*y^2 or x^2 + 960*y^2. This sequence corresponds to those representable by the first form, and A325090 corresponds to those representable by the second form. %H A325089 David Brink, <a href="https://doi.org/10.1016/j.jnt.2008.04.007">Five peculiar theorems on simultaneous representation of primes by quadratic forms</a>, Journal of Number Theory 129(2) (2009), 464-468, doi:10.1016/j.jnt.2008.04.007, MR 2473893. %H A325089 Rémy Sigrist, <a href="/A325089/a325089.gp.txt">PARI program for A325089</a> %H A325089 Wikipedia, <a href="https://en.wikipedia.org/wiki/Kaplansky%27s_theorem_on_quadratic_forms">Kaplansky's theorem on quadratic forms</a> %e A325089 Regarding 5881: %e A325089 - 5881 is a prime number, %e A325089 - 5881 = 24*240 + 121, %e A325089 - 5881 = 59^2 + 0*59*4 + 150*4^2, %e A325089 - hence 5881 belongs to this sequence. %o A325089 (PARI) See Links section. %Y A325089 See A325067 for similar results. %Y A325089 Cf. A325090. %K A325089 nonn %O A325089 1,1 %A A325089 _Rémy Sigrist_, Mar 28 2019