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 A358084 #11 Nov 02 2022 07:16:04 %S A358084 0,16,88,288,1104,3264,12032,34144,115112,323888,1043360,2903280, %T A358084 9122592,24993552,77246888,209811360,637734248,1726546928,5170075216, %U A358084 13965402144,41331646184,111361083152,326576770784,877687158464,2554653282056,6850500549888,19812687702472,53030550412576 %N A358084 Sum of square end-to-end displacements over all n-step self-avoiding walks of A358036. %C A358084 See A358036 for further details. %e A358084 a(3) = 88 as, in the first quadrant, the three 3-step SAWs that have the first and last visited lattice point being mutually visible are: %e A358084 . %e A358084 X %e A358084 | %e A358084 X---. . X %e A358084 | | | %e A358084 X---. X---. X---.---. %e A358084 . %e A358084 The sum of square end-to-end displacements of these three walks is 1 + 5 + 5 = 11. They can be walked in eight different ways on a square lattice thus a(3) = 11 * 8 = 88. %Y A358084 Cf. A358036, A358083, A001411, A336448. %K A358084 nonn,walk %O A358084 1,2 %A A358084 _Scott R. Shannon_, Oct 30 2022