A297225 Number of 3Xn 0..1 arrays with every 1 horizontally or antidiagonally adjacent to 1 neighboring 1s.

1, 9, 24, 57, 182, 535, 1513, 4415, 12832, 37110, 107661, 312229, 904915, 2623749, 7607302, 22054261, 63940404, 185379485, 537454173, 1558199157, 4517574360, 13097454856, 37972451701, 110090662857, 319177485549, 925367027389

Offset

1,2

Comments

Row 3 of A297224.

Links

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

Formula

Empirical: a(n) = a(n-1) +2*a(n-2) +8*a(n-3) +6*a(n-4) +4*a(n-5) -6*a(n-6) -8*a(n-7) -8*a(n-8) +10*a(n-9) +4*a(n-10) -2*a(n-11) -3*a(n-12) +a(n-13)

Example

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

Crossrefs

Cf. A297224.

Sequence in context: A365190 A079770 A079771 * A258438 A038626 A195970

Adjacent sequences: A297222 A297223 A297224 * A297226 A297227 A297228

Keyword

nonn

Author

R. H. Hardin, Dec 27 2017

Status

approved