A197056 - OEIS

A197056

Number of nX3 0..4 arrays with each element equal to the number its horizontal and vertical neighbors equal to 2

1, 3, 6, 10, 14, 22, 38, 67, 111, 179, 291, 485, 812, 1348, 2220, 3660, 6060, 10053, 16653, 27541, 45541, 75367, 124786, 206574, 341850, 565666, 936146, 1549447, 2564507, 4244263, 7024071, 11624777, 19239384, 31841864, 52698776, 87216664

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OFFSET

1,2

COMMENTS

Every 0 is next to 0 2's, every 1 is next to 1 2's, every 2 is next to 2 2's, every 3 is next to 3 2's, every 4 is next to 4 2's

Column 3 of A197061

LINKS

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

FORMULA

Empirical: a(n) = a(n-1) +2*a(n-4) +a(n-5) +a(n-6)

EXAMPLE

Some solutions for n=4

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

..2..3..2....1..2..2....1..1..0....1..2..2....2..2..1....0..1..1....2..2..2

..2..3..2....0..1..1....2..2..1....1..2..2....1..1..0....1..2..2....2..4..2

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

CROSSREFS

Sequence in context: A025206 A049989 A330258 * A104619 A194037 A194101

Adjacent sequences: A197053 A197054 A197055 * A197057 A197058 A197059

KEYWORD

nonn

AUTHOR

R. H. Hardin Oct 09 2011

STATUS

approved