A305771 Number of n X 3 0..1 arrays with every element unequal to 0, 1, 2, 3, 5 or 7 king-move adjacent elements, with upper left element zero.

4, 23, 81, 292, 1096, 4172, 15953, 61111, 234288, 898583, 3447045, 13224257, 50735544, 194653051, 746816146, 2865285427, 10993168588, 42177249636, 161820597240, 620853918472, 2382018289657, 9139044147504, 35063597098216

Offset

1,1

Comments

Column 3 of A305776.

Links

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

Formula

Empirical: a(n) = 4*a(n-1) +a(n-2) -a(n-3) -20*a(n-4) -8*a(n-5) +26*a(n-6) +14*a(n-7) -12*a(n-8) +11*a(n-9) +23*a(n-10) -8*a(n-11) -24*a(n-12) -10*a(n-13) +7*a(n-14) -10*a(n-15) -8*a(n-16).

Example

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

Crossrefs

Cf. A305776.

Sequence in context: A219933 A304305 A316204 * A219465 A317120 A220647

Adjacent sequences: A305768 A305769 A305770 * A305772 A305773 A305774

Keyword

nonn

Author

R. H. Hardin, Jun 10 2018

Status

approved