A305956 Number of nX3 0..1 arrays with every element unequal to 1, 2, 3, 4, 5 or 7 king-move adjacent elements, with upper left element zero.

1, 25, 132, 919, 6030, 39985, 264680, 1752681, 11604776, 76839977, 508784004, 3368840487, 22306294686, 147697925509, 977960616520, 6475425877913, 42876103097980, 283897963371645, 1879789621111676, 12446757199974599

Offset

1,2

Comments

Column 3 of A305961.

Links

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

Formula

Empirical: a(n) = 4*a(n-1) +17*a(n-2) +14*a(n-3) -54*a(n-4) -135*a(n-5) -107*a(n-6) -58*a(n-7) -39*a(n-8) -11*a(n-9) for n>10

Example

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

Crossrefs

Cf. A305961.

Sequence in context: A232873 A232856 A232792 * A367104 A364194 A317217

Adjacent sequences: A305953 A305954 A305955 * A305957 A305958 A305959

Keyword

nonn

Author

R. H. Hardin, Jun 15 2018

Status

approved