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 A338126 #13 Oct 14 2020 23:16:32 %S A338126 5,20,21,80,92,93,304,392,408,409,1168,1684,1832,1852,1853,4348,7036, %T A338126 8084,8308,8332,8333,16336,29396,35752,37620,37936,37964,37965,60208, %U A338126 120776,155756,168768,171808,172232,172264,172265,223352,497196,677856,758340,782344,786972,787520,787556,787557 %N A338126 Triangle read by rows: T(n,w) is the number of n-step self avoiding walks on a 3D cubic lattice confined between two infinite planes a distance w apart where the walk starts on one of the planes. %H A338126 Scott R. Shannon, <a href="/A338126/a338126_1.txt">Full data table for n=1 to n=15</a>. %F A338126 For w>=n, T(n,w) = A116904(n). %e A338126 T(2,1) = 20 as after one step towards the opposite plane the walk must turn along that plane; this eliminates the 2-step straight walk in that direction, so the total number of walks is A116904(2) - 1 = 21 - 1 = 20. %e A338126 The table begins: %e A338126 5; %e A338126 20,21; %e A338126 80,92,93; %e A338126 304,392,408,409; %e A338126 1168,1684,1832,1852,1853; %e A338126 4348,7036,8084,8308,8332,8333; %e A338126 16336,29396,35752,37620,37936,37964,37965; %e A338126 60208,120776,155756,168768,171808,172232,172264,172265; %e A338126 223352,497196,677856,758340,782344,786972,787520,787556,787557; %e A338126 817852,2026220,2920764,3379476,3545108,3586040,3592736,3593424,3593464,3593465; %Y A338126 Cf. A338125 (start between planes), A116904 (w->infinity), A001412, A337023, A337400, A039648. %K A338126 nonn,tabl %O A338126 1,1 %A A338126 _Scott R. Shannon_, Oct 11 2020