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 A054227 #8 Jan 25 2022 21:49:34 %S A054227 1,1,2,2,6,10,19,32,58,105,194,364,682,1295,2467,4723,9059,17448, %T A054227 33706,65256,126643,246179,479336,934603,1824646,3566467,6978040, %U A054227 13666391,26788334,52551600,103168475,202676349,398411711,783639902,1542192977 %N A054227 Number of positive integers <= 2^n of form x^2 + 13 y^2. %Y A054227 Cf. A247881. %K A054227 nonn %O A054227 0,3 %A A054227 _David W. Wilson_