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 A031401 #10 Jan 27 2021 07:28:50 %S A031401 1,2,4,8,4,4,4,4,4,4,4 %N A031401 Period of continued fraction for sqrt(A031400(n)). %Y A031401 Cf. A031400. %K A031401 nonn,more %O A031401 1,2 %A A031401 _David W. Wilson_ %E A031401 a(10)-a(11) from _Chai Wah Wu_, Jan 26 2021