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 A325077 #13 Apr 12 2019 18:53:16 %S A325077 43,103,181,277,439,673,751,823,1039,1063,1117,1429,1453,1759,1993, %T A325077 1999,2131,2287,2311,2467,2521,2539,2617,2833,2851,2857,3067,3163, %U A325077 3457,3559,3613,3637,3847,3943,4021,4027,4177,4261,4339,4723,4783,4861,5113,5119,5197 %N A325077 Prime numbers congruent to 4, 10 or 25 modulo 39 representable by x^2 + x*y + 10*y^2. %C A325077 Brink showed that prime numbers congruent to 4, 10 or 25 modulo 39 are representable by exactly one of the quadratic forms x^2 + x*y + 10*y^2 or x^2 + x*y + 127*y^2. This sequence corresponds to those representable by the first form, and A325078 corresponds to those representable by the second form. %H A325077 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 A325077 Rémy Sigrist, <a href="/A325077/a325077.gp.txt">PARI program for A325077</a> %H A325077 Wikipedia, <a href="https://en.wikipedia.org/wiki/Kaplansky%27s_theorem_on_quadratic_forms">Kaplansky's theorem on quadratic forms</a> %e A325077 Regarding 43: %e A325077 - 43 is a prime number, %e A325077 - 43 = 39 + 4, %e A325077 - 43 = 1^2 + 1*2 + 10*2^2, %e A325077 - hence 43 belongs to this sequence. %o A325077 (PARI) See Links section. %Y A325077 See A325067 for similar results. %Y A325077 Cf. A325078. %K A325077 nonn %O A325077 1,1 %A A325077 _Rémy Sigrist_, Mar 28 2019