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 A054173 #13 Jan 24 2022 04:10:28 %S A054173 0,0,1,1,4,5,10,18,35,65,120,225,430,814,1549,2981,5739,11084,21474, %T A054173 41663,81033,157830,307912,601482,1176314,2302911,4513106,8851907, %U A054173 17376317,34134944,67101922,131990741,259779732,511566355,1007901666 %N A054173 Number of positive integers <= 2^n of form 4 x^2 + 9 y^2. %H A054173 <a href="/index/Qua#quadpop">Index entries for sequences related to populations of quadratic forms</a> %Y A054173 Cf. A020684. %K A054173 nonn %O A054173 0,5 %A A054173 _David W. Wilson_