OFFSET
1,2
COMMENTS
Row 4 of A264945.
LINKS
Christoph Koutschan, Table of n, a(n) for n = 1..80 (first 20 terms from R. H. Hardin).
M. Kauers and C. Koutschan, Some D-finite and some possibly D-finite sequences in the OEIS, arXiv:2303.02793 [cs.SC], 2023.
EXAMPLE
Some solutions for n=4:
0 1 0 2 0 1 2 0 0 1 2 0 0 1 0 1 0 1 2 0
2 0 3 1 3 0 1 2 0 3 1 3 0 2 3 1 3 1 0 3
2 3 2 1 3 2 3 1 3 2 0 1 3 1 3 2 2 3 1 2
1 3 0 3 1 2 3 0 2 1 2 3 2 0 2 3 3 1 0 2
MATHEMATICA
cols = Tuples[{0, 1, 2, 3}, 4];
tmat = Table[If[Or @@ MapThread[SameQ, cols[[{i, j}]]], 0, 1], {i, 256}, {j, 256}];
vec = vvec = ((x^Count[#, 0] * y^Count[#, 1] * z^Count[#, 2]) & /@ cols);
Prepend[Table[vec = Expand[vvec*(tmat.vec)]; Coefficient[Total[vec], (x*y*z)^n]/24, {n, 2, 10}], 1]
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 29 2015
STATUS
approved