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 A046171 #15 Feb 16 2025 08:32:39
%S A046171 1,2,5,13,36,98,272,740,2034,5513,15037,40617,110188,296806,802075,
%T A046171 2155667,5808335,15582342,41889578,112212146,301100754,805570061,
%U A046171 2158326727,5768299665,15435169364,41214098278,110164686454
%N A046171 Number of inequivalent self-avoiding walks of length n on a 2-D lattice which start at origin, take first step in {+1,0} direction and if any steps are vertical, a step up is taken before a step down.
%H A046171 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Self-AvoidingWalk.html">Self-Avoiding Walk.</a>
%F A046171 a(n) = (A001411(n)+4)/8.
%Y A046171 Cf. A001411, A046170.
%K A046171 nonn,walk,easy,nice
%O A046171 1,2
%A A046171 _Eric W. Weisstein_
%E A046171 More terms from _Stephen A. Silver_