A297545 Number of 2 X n 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 2 or 3 neighboring 1s.

1, 2, 11, 24, 38, 105, 381, 1067, 2676, 7533, 22732, 65556, 183281, 521969, 1510877, 4344326, 12399075, 35475604, 101864678, 292266497, 837202865, 2398735503, 6877922768, 19720368509, 56523514608, 162009389860, 464424317089

Offset

1,2

Comments

Row 2 of A297544.

Links

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

Formula

Empirical: a(n) = 3*a(n-1) - 2*a(n-2) + 5*a(n-3) + 6*a(n-4) - 16*a(n-5) - 12*a(n-6).

Empirical g.f.: x*(1 - x + 7*x^2 - 10*x^3 - 28*x^4 - 12*x^5) / (1 - 3*x + 2*x^2 - 5*x^3 - 6*x^4 + 16*x^5 + 12*x^6). - Colin Barker, Mar 22 2018

Example

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

Crossrefs

Cf. A297544.

Sequence in context: A193245 A041803 A220281 * A256905 A294547 A294557

Adjacent sequences: A297542 A297543 A297544 * A297546 A297547 A297548

Keyword

nonn

Author

R. H. Hardin, Dec 31 2017

Status

approved