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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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 4 of A208050.

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..210

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: A102231 A127089 A241769 * A198598 A215916 A068102

Adjacent sequences:  A208043 A208044 A208045 * A208047 A208048 A208049

KEYWORD

nonn

AUTHOR

R. H. Hardin, Feb 22 2012

STATUS

approved

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Last modified May 23 11:05 EDT 2019. Contains 323513 sequences. (Running on oeis4.)