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 A077482 #33 May 23 2025 17:12:43 %S A077482 1,2,11,25,95,228,752,1860,5741,14477,42939,109758,317147,818229, %T A077482 2322512,6030293,16900541,44079555,122379267,320227677,882687730, %U A077482 2315257359,6346076015,16675422679,45502168379,119728011251,325510252108,857400725204 %N A077482 Number of self-avoiding walks on square lattice trapped after n steps. %C A077482 Only 1/8 of all possible walks is counted by selecting the first step in +x direction and requiring the first step changing y to be positive. %D A077482 See references given for A001411. %H A077482 Hugo Pfoertner, <a href="https://www.randomwalk.de/stw2d.html">Results for the 2D Self-Trapping Random Walk</a> %H A077482 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Self-AvoidingWalk.html">Self-Avoiding Walk.</a> %e A077482 a(7) = 1 because there is only 1 self-trapping walk with 7 steps: (0,0)(1,0)(1,1)(1,2)(0,2)(-1,2)(-1,1)(0,1); a(8) = 2 because there are 2 self-trapping walks with 8 steps: (0,0)(1,0)(2,0)(2,1)(2,2)(1,2)(0,2)(0,1)(1,1) and (0,0)(1,0)(1,1)(2,1)(3,1)(3,0)(3,-1)(2,-1)(2,0). %o A077482 (Fortran) c See Hugo Pfoertner link. %Y A077482 Cf. A001411, A046661, A174517, A322831. %K A077482 more,nonn,walk %O A077482 7,2 %A A077482 _Hugo Pfoertner_, Nov 07 2002 %E A077482 a(26)-a(28) from _Alois P. Heinz_, Jun 16 2011 %E A077482 a(29)-a(34) from _Bert Dobbelaere_, Jan 03 2019