A224035 Number of n X 5 0..1 arrays with antidiagonals unimodal and rows and diagonals nondecreasing.

6, 26, 85, 252, 734, 2149, 6321, 18673, 55373, 164729, 491332, 1468446, 4395388, 13170815, 39497285, 118511408, 355728667, 1068051097, 3207330581, 9632722080, 28932821313, 86907496260, 261060029437, 784214341324, 2355790958452

Offset

1,1

Comments

Column 5 of A224038.

Links

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

Formula

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

Empirical g.f.: x*(6 - 10*x - 11*x^2 - 4*x^3 + 10*x^4 + 18*x^5 + 3*x^6 - 14*x^7 - 4*x^9) / ((1 - 2*x)*(1 - 4*x + 2*x^2 + 3*x^3 - x^5 + 2*x^6 + 4*x^8)). - Colin Barker, Aug 26 2018

Example

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

Crossrefs

Cf. A224038.

Sequence in context: A094162 A229572 A316160 * A172207 A060101 A036422

Adjacent sequences: A224032 A224033 A224034 * A224036 A224037 A224038

Keyword

nonn

Author

R. H. Hardin, Mar 30 2013

Status

approved