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 A148140 #4 Dec 28 2023 19:48:54
%S A148140 1,1,2,4,11,29,79,239,717,2308,7297,24044,80190,272169,937998,3238896,
%T A148140 11395781,40306202,144327012,518753441,1877343545,6847992964,
%U A148140 25113561672,92664740665,342898523397,1275918429545,4768716120748,17899948765010,67407916028455,254582546853587,965161647585492,3670755986440919
%N A148140 Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 0), (-1, 0, -1), (-1, 0, 1), (0, 1, -1), (1, 0, 0)}.
%H A148140 A. Bostan and M. Kauers, 2008. Automatic Classification of Restricted Lattice Walks, <a href="http://arxiv.org/abs/0811.2899">ArXiv 0811.2899</a>.
%t A148140 aux[i_Integer, j_Integer, k_Integer, n_Integer] := Which[Min[i, j, k, n] < 0 || Max[i, j, k] > n, 0, n == 0, KroneckerDelta[i, j, k, n], True, aux[i, j, k, n] = aux[-1 + i, j, k, -1 + n] + aux[i, -1 + j, 1 + k, -1 + n] + aux[1 + i, j, -1 + k, -1 + n] + aux[1 + i, j, 1 + k, -1 + n] + aux[1 + i, 1 + j, k, -1 + n]]; Table[Sum[aux[i, j, k, n], {i, 0, n}, {j, 0, n}, {k, 0, n}], {n, 0, 10}]
%K A148140 nonn,walk
%O A148140 0,3
%A A148140 _Manuel Kauers_, Nov 18 2008