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 A150552 #4 Dec 28 2023 23:59:17
%S A150552 1,2,7,26,105,442,1920,8525,38480,175927,812470,3783046,17733619,
%T A150552 83598750,395976575,1883262667,8988385280,43031566795,206568684223,
%U A150552 993983881425,4793114652198,23157079690297,112071405946713,543225406892426,2636805762921490,12815498860843351,62359888275586999,303770986781638654
%N A150552 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, 1), (-1, 0, 1), (0, 0, 1), (1, 0, -1), (1, 1, 0)}.
%H A150552 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 A150552 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, -1 + j, k, -1 + n] + aux[-1 + i, j, 1 + k, -1 + n] + aux[i, j, -1 + k, -1 + n] + aux[1 + i, j, -1 + k, -1 + n] + aux[1 + i, 1 + j, -1 + k, -1 + n]]; Table[Sum[aux[i, j, k, n], {i, 0, n}, {j, 0, n}, {k, 0, n}], {n, 0, 10}]
%K A150552 nonn,walk
%O A150552 0,2
%A A150552 _Manuel Kauers_, Nov 18 2008