A316752 - OEIS

A316752

Number of nX3 0..1 arrays with every element unequal to 1, 2, 4, 6, 7 or 8 king-move adjacent elements, with upper left element zero.

1, 9, 15, 17, 79, 185, 315, 970, 2366, 4927, 12747, 31483, 71152, 174182, 426352, 999419, 2406348, 5836950, 13890672, 33315051, 80359905, 192347104, 461162125, 1109224787, 2660354703, 6380696205, 15327646223, 36784405441, 88255373344

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,2

COMMENTS

Column 3 of A316757.

LINKS

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

FORMULA

Empirical: a(n) = 3*a(n-2) +12*a(n-3) +5*a(n-4) -23*a(n-5) -50*a(n-6) -25*a(n-7) +40*a(n-8) +70*a(n-9) +32*a(n-10) -25*a(n-11) -25*a(n-12) -5*a(n-13) +4*a(n-14) -a(n-15) -2*a(n-16) for n>17

EXAMPLE

Some solutions for n=5

..0..0..1. .0..0..0. .0..1..0. .0..0..0. .0..1..1. .0..0..1. .0..1..0

..0..1..0. .0..1..0. .1..0..0. .0..1..0. .0..0..0. .0..1..0. .0..1..0

..0..0..0. .0..0..0. .1..1..0. .0..0..0. .0..0..0. .0..0..0. .0..0..0

..0..0..1. .1..0..0. .1..0..1. .0..1..0. .0..1..0. .0..1..0. .1..0..0

..0..1..0. .0..1..0. .0..1..1. .0..0..1. .0..0..1. .0..1..0. .0..1..0

CROSSREFS

Cf. A316757.

Sequence in context: A037002 A071149 A289689 * A358725 A358576 A373995

Adjacent sequences: A316749 A316750 A316751 * A316753 A316754 A316755

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jul 12 2018

STATUS

approved