A304889 Number of nX3 0..1 arrays with every element unequal to 0, 2, 3, 4 or 7 king-move adjacent elements, with upper left element zero.

1, 8, 11, 40, 94, 291, 776, 2269, 6275, 17985, 50548, 143589, 405620, 1149709, 3252139, 9211083, 26070305, 73816122, 208963020, 591618663, 1674877081, 4741816884, 13424434567, 38006135552, 107599067346, 304624934972

Offset

1,2

Comments

Column 3 of A304894.

Links

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

Formula

Empirical: a(n) = 3*a(n-1) +3*a(n-2) -7*a(n-3) -8*a(n-4) -8*a(n-5) +26*a(n-6) -13*a(n-7) -16*a(n-8) +76*a(n-9) -33*a(n-10) -22*a(n-11) +27*a(n-12) -23*a(n-13) +11*a(n-14) +7*a(n-15) -5*a(n-16) +5*a(n-17) -2*a(n-18) -2*a(n-19) for n>20

Example

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

Crossrefs

Cf. A304894.

Sequence in context: A160416 A056873 A303883 * A192427 A258285 A166673

Adjacent sequences: A304886 A304887 A304888 * A304890 A304891 A304892

Keyword

nonn

Author

R. H. Hardin, May 20 2018

Status

approved