login
A208046
Number of n X 4 0..3 arrays with new values 0..3 introduced in row major order and no element equal to any horizontal, vertical or antidiagonal neighbor (colorings ignoring permutations of colors).
2
5, 32, 244, 1904, 14976, 118096, 931968, 7356288, 58068800, 458389760, 3618506752, 28564366592, 225486229504, 1779981604864, 14051122574336, 110919150841856, 875592537571328, 6911901929525248, 54562352063938560, 430713614487224320
OFFSET
1,1
COMMENTS
Column 4 of A208050.
LINKS
FORMULA
Empirical: a(n) = 12*a(n-1) - 40*a(n-2) + 68*a(n-3) - 64*a(n-4) for n>5.
Empirical g.f.: x*(5 - 28*x + 60*x^2 - 84*x^3 + 32*x^4) / (1 - 12*x + 40*x^2 - 68*x^3 + 64*x^4). - Colin Barker, Mar 06 2018
EXAMPLE
Some solutions for n=4:
0 1 2 1 0 1 2 0 0 1 0 1 0 1 2 3 0 1 2 3
2 3 0 2 2 0 1 2 2 3 2 3 2 3 0 1 2 3 0 1
1 2 1 3 1 3 0 1 0 1 0 1 0 1 3 0 1 2 3 2
3 0 2 0 2 1 2 3 2 3 2 0 2 0 2 1 3 1 0 1
CROSSREFS
Cf. A208050.
Sequence in context: A367281 A127089 A241769 * A198598 A369785 A215916
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 22 2012
STATUS
approved