A297501 Number of nX3 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 1 or 2 neighboring 1s.

4, 31, 110, 531, 2534, 11405, 53175, 246040, 1135117, 5253716, 24286811, 112274796, 519155469, 2400230989, 11097385328, 51309028043, 237225520918, 1096808926323, 5071081279846, 23446053720513, 108402467083427, 501197081280420

Offset

1,1

Comments

Column 3 of A297506.

Links

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

Formula

Empirical: a(n) = a(n-1) +5*a(n-2) +37*a(n-3) +63*a(n-4) +101*a(n-5) -45*a(n-6) -198*a(n-7) -254*a(n-8) -40*a(n-9) +88*a(n-10) +96*a(n-11)

Example

Some solutions for n=7
..1..0..1. .1..1..0. .0..0..0. .1..1..0. .1..1..0. .0..1..0. .1..0..0
..0..1..0. .0..0..0. .0..0..0. .0..0..1. .1..0..0. .1..1..1. .0..1..1
..0..1..0. .1..0..0. .1..1..0. .0..0..0. .0..0..0. .0..0..0. .0..0..0
..1..1..1. .1..1..0. .0..0..0. .1..1..0. .0..1..1. .1..0..0. .1..1..1
..0..0..0. .0..1..0. .0..0..0. .1..0..0. .0..0..0. .1..1..0. .0..1..0
..0..1..0. .0..1..1. .1..1..0. .0..0..0. .0..1..0. .0..0..0. .0..1..0
..0..1..1. .0..0..1. .0..0..0. .1..1..0. .1..0..0. .1..1..0. .1..0..1

Crossrefs

Cf. A297506.

Sequence in context: A210377 A211629 A263760 * A296734 A220284 A059938

Adjacent sequences: A297498 A297499 A297500 * A297502 A297503 A297504

Keyword

nonn

Author

R. H. Hardin, Dec 31 2017

Status

approved