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 A346228 #7 Jul 12 2021 21:46:37 %S A346228 1,1,8,57,372,2332,14960,102173,732124,5306652,38253888,275352960, %T A346228 1996376544,14642264736,108536296800,809764874325,6057499056204, %U A346228 45368515203628,340472040666080,2563725956556584,19381407270110656,147036877912623840,1118355187220657856 %N A346228 Number of n-step 7-dimensional nonnegative lattice walks starting at the origin and using steps that increment all components or decrement one component by 1. %H A346228 Alois P. Heinz, <a href="/A346228/b346228.txt">Table of n, a(n) for n = 0..90</a> %F A346228 a(n) == 1 (mod 7). %p A346228 b:= proc(n, l) option remember; `if`(n=0, 1, (k-> `if`(n>min(l), %p A346228 add(`if`(l[i]=0, 0, b(n-1, sort(subsop(i=l[i]-1, l)))), %p A346228 i=1..k)+b(n-1, map(x-> x+1, l)), (k+1)^n))(nops(l))) %p A346228 end: %p A346228 a:= n-> b(n, [0$7]): %p A346228 seq(a(n), n=0..27); %Y A346228 Column k=7 of A335570. %K A346228 nonn,walk %O A346228 0,3 %A A346228 _Alois P. Heinz_, Jul 11 2021