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 A054229 #8 Jan 25 2022 21:49:28 %S A054229 1,1,2,2,5,9,16,27,52,91,173,322,606,1152,2191,4191,8060,15540,30018, %T A054229 58161,112891,219479,427440,833615,1627752,3182068,6226916,12196740, %U A054229 23910690,46911434,92104753,180957883,355748937,699779680,1377255678 %N A054229 Number of positive integers <= 2^n of form x^2 + 15 y^2. %Y A054229 Cf. A243173. %K A054229 nonn %O A054229 0,3 %A A054229 _David W. Wilson_