A300375 Number of nX3 0..1 arrays with every element equal to 0, 2 or 3 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.

1, 2, 4, 11, 8, 58, 131, 306, 936, 2435, 6683, 18093, 49663, 134666, 367314, 1002020, 2728817, 7439403, 20275261, 55264984, 150614904, 410527337, 1118909399, 3049617734, 8311952136, 22654640136, 61746476769, 168293237171, 458692748831

Offset

1,2

Comments

Column 3 of A300380.

Links

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

Formula

Empirical: a(n) = 3*a(n-2) +9*a(n-3) +9*a(n-4) +3*a(n-5) -8*a(n-6) -a(n-7) -18*a(n-8) -24*a(n-9) -45*a(n-10) -10*a(n-11) -15*a(n-12) +39*a(n-13) -21*a(n-14) +9*a(n-15) -7*a(n-16) -13*a(n-17) +14*a(n-18) -5*a(n-19) +3*a(n-20) -2*a(n-22) +a(n-23) for n>25

Example

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

Crossrefs

Cf. A300380.

Sequence in context: A246164 A124183 A218643 * A075488 A363702 A136995

Adjacent sequences: A300372 A300373 A300374 * A300376 A300377 A300378

Keyword

nonn

Author

R. H. Hardin, Mar 04 2018

Status

approved