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 A039648 #20 Feb 20 2021 16:10:25 %S A039648 1,3,9,33,123,489,1947,7977,32817,137253,576993,2452071,10468245, %T A039648 45032733,194475321,844608567,3680153043,16105438515,70677344403, %U A039648 311242931097,1373860647453,6081635195553 %N A039648 Number of n-step self-avoiding paths on the first octant of a 3-dimensional cubic lattice, starting at the origin. %Y A039648 Cf. A039618, A005566. %K A039648 nonn,walk,more %O A039648 0,2 %A A039648 _David W. Wilson_ %E A039648 a(19)-a(21) from _Scott R. Shannon_, Aug 14 2020 %E A039648 Title clarified by _Sean A. Irvine_, Feb 20 2021