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 A078799 #9 Jul 16 2025 23:38:22 %S A078799 1,6,35,150,627,2318,8400,28624,96049,311002,994899,3111570,9638347, %T A078799 29398762,88985840,266359752,792360385,2337329116,6859721431, %U A078799 20000471236,58067533570,167703151726 %N A078799 Sum of square displacements over all self-avoiding walks on square lattice trapped after n steps. %C A078799 The mean squared displacement is given by a(n)/A077482(n) See also "Average Euclidean and Squared End Point Distance" at link %H A078799 Hugo Pfoertner, <a href="http://www.randomwalk.de/stw2d.html">Results for the 2D Self-Trapping Random Walk</a> %e A078799 a(9)=35 because the A077482(9)=11 different self-trapping walks stop at 5*(0,1)->d^2=1, 2*(1,2)->d^2=5, 2*(2,1)->d^2=5, (-1,0)->d^2=1 (3,0)->d^2=9. a(9)=5*1+2*5+2*5+1+9=35 See "Enumeration of all short self-trapping walks" at link %o A078799 (Fortran) c Program for distance counting available at link. %Y A078799 Cf. A077482, A078797, A078800 (corresponding Manhattan distance sum). %K A078799 nonn,more %O A078799 7,2 %A A078799 _Hugo Pfoertner_, Dec 26 2002 %E A078799 a(26)-a(28) from _Sean A. Irvine_, Jul 16 2025