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 A034040 #7 Jul 08 2025 20:04:23 %S A034040 9,16,18,25,36,49,50,72,81,98,99,100,121,126,144,162,169,196,198,200, %T A034040 207,224,225,252,275,288,289,324,333,338,350,361,387,392,396,400,414, %U A034040 441,450,477,504,512,522,539,550,575,576,578,625,639,648 %N A034040 Imprimitively but not primitively represented by (x^2+xy+2y^2, x>=0, y>=0). %Y A034040 Cf. A034035-A034042. %K A034040 nonn %O A034040 0,1 %A A034040 _N. J. A. Sloane_ %E A034040 Definition corrected by _N. J. A. Sloane_, Apr 30 2015