A297428 Number of nX5 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 2 neighboring 1s.

1, 18, 43, 105, 535, 1673, 5108, 19690, 66529, 219719, 782043, 2689834, 9138448, 31787848, 109656609, 376254515, 1300385669, 4486150451, 15444407832, 53285238222, 183782980324, 633397239002, 2184333019339, 7532734275806

Offset

1,2

Comments

Column 5 of A297431.

Links

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

Formula

Empirical: a(n) = 2*a(n-1) +2*a(n-2) +24*a(n-3) -22*a(n-4) -40*a(n-5) -163*a(n-6) -40*a(n-7) +76*a(n-8) +246*a(n-9) +160*a(n-10) -57*a(n-11) -115*a(n-12) -50*a(n-13) +18*a(n-14) +12*a(n-15) -33*a(n-16) +4*a(n-17) +5*a(n-18) +7*a(n-19) -3*a(n-20)

Example

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

Crossrefs

Cf. A297431.

Sequence in context: A044095 A044476 A045264 * A049067 A114814 A299383

Adjacent sequences: A297425 A297426 A297427 * A297429 A297430 A297431

Keyword

nonn

Author

R. H. Hardin, Dec 30 2017

Status

approved