A300918 Number of nX3 0..1 arrays with every element equal to 0, 2, 3, 4 or 5 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.

1, 5, 20, 76, 290, 1245, 5160, 21819, 91713, 388059, 1639111, 6934811, 29326929, 124078694, 524899537, 2220794401, 9395650615, 39752075589, 168185729492, 711577787970, 3010611147958, 12737611709683, 53891601910235

Offset

1,2

Comments

Column 3 of A300923.

Links

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

Formula

Empirical: a(n) = 2*a(n-1) +11*a(n-2) +a(n-3) -17*a(n-4) -46*a(n-5) -68*a(n-6) -42*a(n-7) +4*a(n-8) +43*a(n-9) +28*a(n-10) -34*a(n-11) -12*a(n-12) +8*a(n-13) +46*a(n-14) +22*a(n-15) +15*a(n-16) -2*a(n-17) -2*a(n-18) -3*a(n-19) -a(n-21) for n>22

Example

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

Crossrefs

Cf. A300923.

Sequence in context: A000758 A005283 A057552 * A269708 A295347 A270985

Adjacent sequences: A300915 A300916 A300917 * A300919 A300920 A300921

Keyword

nonn

Author

R. H. Hardin, Mar 15 2018

Status

approved