A297340 Number of 3Xn 0..1 arrays with every 1 horizontally or antidiagonally adjacent to 0 or 2 neighboring 1s.

8, 21, 96, 334, 1310, 4888, 18604, 70255, 266149, 1006942, 3811738, 14425839, 54601094, 206654096, 782157108, 2960335613, 11204414255, 42406931107, 160503589065, 607480807913, 2299219387602, 8702183730269, 32936397114024

Offset

1,1

Comments

Row 3 of A297338.

Links

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

Formula

Empirical: a(n) = 2*a(n-1) +7*a(n-2) +2*a(n-3) -8*a(n-4) -12*a(n-5) +4*a(n-7) +5*a(n-8) -2*a(n-9) +2*a(n-10) -a(n-12)

Example

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

Crossrefs

Cf. A297338.

Sequence in context: A188700 A054855 A220611 * A220580 A100903 A358720

Adjacent sequences: A297337 A297338 A297339 * A297341 A297342 A297343

Keyword

nonn

Author

R. H. Hardin, Dec 28 2017

Status

approved