A297973 Number of nX3 0..1 arrays with every element equal to 2, 3, 4 or 5 king-move adjacent elements, with upper left element zero.

0, 3, 8, 20, 124, 501, 2410, 11304, 53108, 251672, 1189220, 5629257, 26643680, 126113485, 596993794, 2825991213, 13377659542, 63327123116, 299778122298, 1419092188131, 6717710538398, 31800362165742, 150536862803822

Offset

1,2

Comments

Column 3 of A297978.

Links

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

Formula

Empirical: a(n) = 4*a(n-1) +10*a(n-2) -22*a(n-3) -58*a(n-4) +51*a(n-5) +136*a(n-6) -75*a(n-7) -137*a(n-8) +70*a(n-9) +57*a(n-10) -33*a(n-11) -2*a(n-12) +8*a(n-13) for n>15

Example

Some solutions for n=7
..0..0..1. .0..1..1. .0..0..1. .0..0..0. .0..1..1. .0..0..0. .0..0..0
..0..1..1. .0..0..1. .0..1..1. .0..1..0. .0..0..1. .0..1..0. .0..1..0
..1..0..1. .0..1..0. .0..0..1. .1..1..1. .1..1..1. .1..1..1. .1..1..0
..1..0..0. .1..0..1. .0..1..1. .1..0..0. .1..0..1. .0..0..1. .0..1..0
..0..1..0. .1..1..0. .0..0..0. .1..0..0. .0..0..1. .0..1..0. .0..0..0
..0..1..1. .0..1..0. .1..1..0. .1..1..0. .1..0..1. .1..0..0. .1..1..1
..0..0..1. .0..0..0. .1..1..1. .1..0..0. .1..1..1. .1..1..0. .1..1..1

Crossrefs

Cf. A297978.

Sequence in context: A110861 A027320 A027319 * A291176 A066212 A171437

Adjacent sequences: A297970 A297971 A297972 * A297974 A297975 A297976

Keyword

nonn

Author

R. H. Hardin, Jan 10 2018

Status

approved