A296316 Number of n X 4 0..1 arrays with each 1 horizontally, vertically or antidiagonally adjacent to 1 neighboring 1.

4, 27, 96, 434, 1970, 8470, 37431, 164807, 723019, 3180521, 13980961, 61446863, 270126432, 1187392203, 5219407184, 22943336005, 100852689192, 443321760393, 1948727874003, 8566095221354, 37654312064817, 165518509370616

Offset

1,1

Comments

Column 4 of A296320.

Links

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

Formula

Empirical: a(n) = a(n-1) +6*a(n-2) +29*a(n-3) +30*a(n-4) +61*a(n-5) +9*a(n-6) +73*a(n-7) -93*a(n-8) +134*a(n-9) -201*a(n-10) +173*a(n-11) -179*a(n-12) +107*a(n-13) -a(n-14) -30*a(n-15) -15*a(n-16) +22*a(n-17) -3*a(n-18) -2*a(n-19) -a(n-20) +a(n-21).

Example

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

Crossrefs

Cf. A296320.

Sequence in context: A225902 A071174 A092364 * A071175 A352331 A063262

Adjacent sequences: A296313 A296314 A296315 * A296317 A296318 A296319

Keyword

nonn

Author

R. H. Hardin, Dec 10 2017

Status

approved