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 A149310 #4 Dec 27 2023 12:48:55
%S A149310 1,1,4,11,48,175,778,3191,14580,63151,294654,1319254,6238358,28569059,
%T A149310 136366598,634469527,3049781298,14355616375,69371945164,329453045822,
%U A149310 1598618636736,7644778934321,37217389907328,178962814190005,873587837238233,4219559072209261,20642931394250364,100076287992035523
%N A149310 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, 1, 0), (0, 1, -1), (1, -1, 1), (1, 1, 0)}.
%H A149310 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 A149310 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, 1 + j, -1 + k, -1 + n] + aux[i, -1 + j, 1 + k, -1 + n] + aux[1 + i, -1 + j, 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 A149310 nonn,walk
%O A149310 0,3
%A A149310 _Manuel Kauers_, Nov 18 2008