

A229582


Number of defective 3colorings of an n X 4 0..2 array connected horizontally and antidiagonally with exactly one mistake, and colors introduced in rowmajor 0..2 order.


1



6, 116, 1620, 19764, 224532, 2440692, 25745364, 265720500, 2697594516, 27033340788, 268094978388, 2636009007156, 25732468879380, 249667710249204, 2409688805255892, 23151313964420532, 221538858133842324
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OFFSET

1,1


LINKS

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


FORMULA

Empirical: a(n) = 18*a(n1)  81*a(n2) for n>3.
Conjectures from Colin Barker, Sep 19 2018: (Start)
G.f.: 2*x*(3 + 4*x + 9*x^2) / (1  9*x)^2.
a(n) = 4 * 9^(n  2) * (16*n  3) for n>1.
(End)


EXAMPLE

Some solutions for n=3:
..0..1..0..1....0..1..1..2....0..1..0..2....0..1..2..1....0..1..2..0
..0..2..1..2....0..2..0..2....0..1..0..2....0..1..0..1....1..0..1..0
..1..0..1..0....0..2..1..0....1..2..1..2....1..2..0..2....1..2..1..0


CROSSREFS

Column 4 of A229586.
Sequence in context: A278752 A003425 A052465 * A113015 A024275 A287652
Adjacent sequences: A229579 A229580 A229581 * A229583 A229584 A229585


KEYWORD

nonn


AUTHOR

R. H. Hardin, Sep 26 2013


STATUS

approved



