A183547 Number of n X 2 0..2 arrays with each element equal to either the maximum or the minimum of its horizontal and vertical neighbors.

3, 15, 71, 299, 1325, 5845, 25785, 113841, 502523, 2218399, 9793287, 43233099, 190855613, 842545925, 3719480233, 16419916497, 72486917979, 319998782959, 1412657953559, 6236281512443, 27530519336653, 121535484480133

Offset

1,1

Comments

Column 2 of A183554.

Links

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

Formula

Empirical: a(n) = 5*a(n-1) - 3*a(n-2) + 4*a(n-3) - 9*a(n-4) - 13*a(n-6) + 8*a(n-7) + 4*a(n-8) + 7*a(n-9) + 2*a(n-10).

Empirical g.f.: x*(3 + 5*x^2 - 23*x^3 + 10*x^4 - 32*x^5 + 17*x^6 + 13*x^7 + 9*x^8 + 10*x^9) / (1 - 5*x + 3*x^2 - 4*x^3 + 9*x^4 + 13*x^6 - 8*x^7 - 4*x^8 - 7*x^9 - 2*x^10). - Colin Barker, Mar 29 2018

Example

Some solutions for 3 X 2:
..0..0....2..2....1..1....2..2....1..1....0..0....2..1....1..1....0..0....2..2
..1..0....1..2....2..1....0..0....0..1....1..1....2..1....0..0....2..0....0..2
..1..1....1..1....2..1....1..1....0..1....1..1....2..1....1..1....2..0....0..2

Crossrefs

Cf. A183554.

Sequence in context: A359405 A009174 A178345 * A123942 A357161 A290902

Adjacent sequences: A183544 A183545 A183546 * A183548 A183549 A183550

Keyword

nonn

Author

R. H. Hardin, Jan 05 2011

Status

approved