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 A028957 #31 Jul 08 2025 18:58:09 %S A028957 0,1,4,6,9,10,15,16,19,24,25,31,34,36,40,46,49,51,54,60,61,64,69,76, %T A028957 79,81,85,90,94,96,100,106,109,114,115,121,124,135,136,139,141,144, %U A028957 150,151,159,160,166,169,171,181,184,186,190,196,199,204,211,214,216,225 %N A028957 Numbers represented by quadratic form with Gram matrix [ 2, 1; 1, 8 ] (divided by 2). %C A028957 Nonnegative integers of the form x^2 + x*y + 4y^2, discriminant -15. - _Ray Chandler_, Jul 12 2014 %H A028957 N. J. A. Sloane et al., <a href="https://oeis.org/wiki/Binary_Quadratic_Forms_and_OEIS">Binary Quadratic Forms and OEIS</a> (Index to related sequences, programs, references) %Y A028957 Primes are in A033212. %K A028957 nonn %O A028957 1,3 %A A028957 _N. J. A. Sloane_ %E A028957 More terms from Larry Reeves (larryr(AT)acm.org), Mar 29 2000