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 A337400 #23 Feb 01 2021 00:18:33 %S A337400 6,26,6,98,30,6,330,146,30,6,1130,658,150,30,6,3746,2858,722,150,30,6, %T A337400 12802,11802,3450,726,150,30,6,42498,48282,15930,3530,726,150,30,6, %U A337400 143610,193714,72522,16826,3534,726,150,30,6,472242,781114,321794,80010,16922,3534,726,150,30,6 %N A337400 Table read by antidiagonals: T(w,n) is the number of n-step self avoiding walks on a 3D cubic lattice confined inside a tube of cross section 2w X 2w where the walk starts at the middle of the tube. %F A337400 For n <= w, T(w,n) = A001412(n). %e A337400 T(1,2) = 26 as after a step in one of the four directions toward the tube's side the walk must turn along the side; this eliminates the 2-step straight walk in those four directions, so the total number of walks is 6*5 - 4 = 26. %e A337400 The table begins: %e A337400 6 26 98 330 1130 3746 12802 42498 143610 472242 1570714 5110426 16779354... %e A337400 6 30 146 658 2858 11802 48282 193714 781114 3114890 12508114 49767002 199252346... %e A337400 6 30 150 722 3450 15930 72522 321794 1415450 6134650 26527690 113725546 487875250... %e A337400 6 30 150 726 3530 16826 80010 373962 1736538 7946946 36158802 162796866 730521658... %e A337400 6 30 150 726 3534 16922 81274 386138 1833018 8615906 40370370 187477426 867587114... %e A337400 6 30 150 726 3534 16926 81386 387834 1851546 8780162 41630146 196172338 923017178... %e A337400 6 30 150 726 3534 16926 81390 387962 1853738 8806962 41893346 198386594 939630954... %e A337400 6 30 150 726 3534 16926 81390 387966 1853882 8809714 41930594 198788354 943314378... %e A337400 6 30 150 726 3534 16926 81390 387966 1853886 8809874 41933970 198838482 943903786... %e A337400 6 30 150 726 3534 16926 81390 387966 1853886 8809878 41934146 198842546 943969482... %e A337400 6 30 150 726 3534 16926 81390 387966 1853886 8809878 41934150 198842738 943974298... %e A337400 6 30 150 726 3534 16926 81390 387966 1853886 8809878 41934150 198842742 943974506... %e A337400 6 30 150 726 3534 16926 81390 387966 1853886 8809878 41934150 198842742 943974510... %Y A337400 Cf. A337401 (start at center of tube's side), A337403 (start at tube's edge), A001412 (w->infinity), A116904, A337023, A259808, A039648. %K A337400 nonn,walk,tabl %O A337400 1,1 %A A337400 _Scott R. Shannon_, Aug 26 2020