

A205468


Number of (n+1) X 2 0..2 arrays with every 2 X 2 subblock having the same number of equal edges, and new values 0..2 introduced in row major order.


2



14, 48, 175, 677, 2709, 11143, 46709, 198483, 851317, 3674723, 15929949, 69254347, 301652741, 1315582371, 5742416845, 25079258843, 109571246421, 478835560339, 2092898539805, 9148671997707, 39994487184037, 174849254952131
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OFFSET

1,1


COMMENTS

Column 1 of A205475.


LINKS

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


FORMULA

Empirical: a(n) = 9*a(n1)  21*a(n2)  11*a(n3) + 66*a(n4)  6*a(n5)  36*a(n6).
Empirical g.f.: x*(14  78*x + 37*x^2 + 264*x^3  105*x^4  180*x^5) / ((1  x)*(1  3*x)*(1  2*x  2*x^2)*(1  3*x  6*x^2)).  Colin Barker, Mar 04 2018


EXAMPLE

Some solutions for n=4:
..0..0....0..0....0..0....0..1....0..0....0..0....0..0....0..0....0..1....0..0
..0..1....0..1....0..1....1..1....1..0....0..0....1..2....1..2....0..2....1..2
..0..1....0..0....1..1....2..1....1..1....0..0....1..0....0..2....1..2....0..2
..1..1....1..0....0..0....1..1....2..2....0..0....2..2....0..1....0..0....0..1
..1..2....1..0....1..0....1..2....2..1....0..0....0..1....0..2....2..1....2..2


CROSSREFS

Cf. A205475.
Sequence in context: A205753 A332606 A232826 * A195966 A337421 A345724
Adjacent sequences: A205465 A205466 A205467 * A205469 A205470 A205471


KEYWORD

nonn


AUTHOR

R. H. Hardin, Jan 27 2012


STATUS

approved



