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A183425 Half the number of n X 2 0..2 arrays with no element equal its row sum plus its column sum mod 3. 1
3, 9, 32, 129, 513, 2048, 8193, 32769, 131072, 524289, 2097153, 8388608, 33554433, 134217729, 536870912, 2147483649, 8589934593, 34359738368, 137438953473, 549755813889, 2199023255552, 8796093022209, 35184372088833, 140737488355328 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 2 of A183429.

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..200

FORMULA

Empirical: a(n)=4*a(n-1) + a(n-3) - 4*a(n-4).

Empirical g.f.: x*(3 - 3*x - 4*x^2 - 2*x^3) / ((1 - x)*(1 - 4*x)*(1 + x + x^2)). - Colin Barker, Mar 29 2018

EXAMPLE

Some solutions for 4 X 2:

..1..2....2..2....0..1....2..1....0..2....1..1....0..0....2..1....1..1....0..2

..0..2....2..2....0..1....1..2....0..0....1..2....0..1....0..1....1..2....1..0

..1..2....2..2....0..1....1..2....1..2....0..2....0..0....2..2....2..2....0..0

..1..1....2..2....0..1....2..1....1..0....1..2....1..0....2..1....2..1....1..2

CROSSREFS

Cf. A183429.

Sequence in context: A193621 A344623 A320180 * A039628 A194530 A324238

Adjacent sequences: A183422 A183423 A183424 * A183426 A183427 A183428

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jan 04 2011

STATUS

approved

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Last modified December 8 03:48 EST 2022. Contains 358672 sequences. (Running on oeis4.)