A202545 Number of n X 4 nonnegative integer arrays each row and column an ascent sequence (interior element no greater than one plus up-steps preceding it).

1, 8, 86, 1094, 15184, 219934, 3249298, 48427802, 724492208, 10855670258, 162764756218, 2441054713126, 36613379378704, 549186530733206, 8237716581278546, 123565284853121186, 1853476648287687712

Offset

1,2

Comments

Column 4 of A202549.

Links

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

Formula

Empirical: a(n) = 36*a(n-1) -492*a(n-2) +3418*a(n-3) -13215*a(n-4) +28650*a(n-5) -32500*a(n-6) +15000*a(n-7).

Empirical g.f.: x*(1 - 28*x + 290*x^2 - 1484*x^3 + 3983*x^4 - 5320*x^5 + 2700*x^6) / ((1 - 2*x)^3*(1 - 5*x)^3*(1 - 15*x)). - Colin Barker, Jun 01 2018

Example

Some solutions for n=5:
..0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..0
..0..1..1..1....0..1..1..0....0..0..0..0....0..1..1..1....0..1..1..1
..0..1..2..1....0..1..1..1....0..0..0..1....0..0..0..0....0..1..2..0
..0..1..0..0....0..0..1..1....0..1..1..0....0..0..1..0....0..1..2..0
..0..1..1..2....0..0..0..1....0..1..0..1....0..0..0..1....0..1..0..2

Crossrefs

Cf. A202549.

Sequence in context: A369505 A268052 A268075 * A131812 A241259 A225314

Adjacent sequences: A202542 A202543 A202544 * A202546 A202547 A202548

Keyword

nonn

Author

R. H. Hardin, Dec 20 2011

Status

approved