A304414 Number of nX3 0..1 arrays with every element unequal to 0, 2, 3, 4 or 5 king-move adjacent elements, with upper left element zero.

1, 8, 23, 103, 520, 2671, 13876, 72399, 378321, 1979531, 10361881, 54254622, 284118654, 1487964150, 7792975441, 40815315514, 213770499606, 1119631248273, 5864130051553, 30713754006040, 160865382297683, 842543809330756

Offset

1,2

Comments

Column 3 of A304419.

Links

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

Formula

Empirical: a(n) = 5*a(n-1) +7*a(n-2) -16*a(n-3) -78*a(n-4) -11*a(n-5) +133*a(n-6) +161*a(n-7) +58*a(n-8) -114*a(n-9) -121*a(n-10) -91*a(n-11) -47*a(n-12) -12*a(n-13) +4*a(n-14) +8*a(n-15) for n>17

Example

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

Crossrefs

Cf. A304419.

Sequence in context: A036562 A320310 A303720 * A305949 A220973 A233470

Adjacent sequences: A304411 A304412 A304413 * A304415 A304416 A304417

Keyword

nonn

Author

R. H. Hardin, May 12 2018

Status

approved