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 A039618 #11 Feb 19 2021 18:35:53 %S A039618 1,0,3,18,138,1278,13410,154584,1919352,25273422,348989058,5011939788, %T A039618 74393974476,1135821378924 %N A039618 Number of 2n-step self-avoiding closed walks on first octant of 3-dimensional cubic lattice, passing through origin. %H A039618 Sean A. Irvine, <a href="https://github.com/archmageirvine/joeis/blob/master/src/irvine/oeis/a039/A039618.java">Java program</a> (github) %Y A039618 Cf. A001409, A034010. %K A039618 nonn,walk,hard,more %O A039618 0,3 %A A039618 _David W. Wilson_ %E A039618 a(11)-a(13) from _Sean A. Irvine_, Feb 19 2021