login
A300177
Number of nX3 0..1 arrays with every element equal to 0, 1, 2, 3, 4, 5, 6 or 7 king-move adjacent elements, with upper left element zero.
1
4, 32, 255, 2033, 16208, 129217, 1030173, 8212978, 65477359, 522013397, 4161713160, 33178950053, 264516722873, 2108839989442, 16812570686523, 134036975068993, 1068599860225264, 8519333271178937, 67919753770243365
OFFSET
1,1
COMMENTS
Column 3 of A300182.
FORMULA
Empirical: a(n) = 7*a(n-1) +7*a(n-2) +6*a(n-3).
Empirical g.f.: -x*(-3*x^2-4*x-4)/(-6*x^3-7*x^2-7*x+1). - Simon Plouffe, Jun 21 2018
EXAMPLE
Some solutions for n=5
..0..1..1. .0..1..1. .0..0..0. .0..1..1. .0..1..0. .0..0..1. .0..0..1
..1..1..0. .0..0..1. .0..1..1. .1..1..0. .0..1..1. .0..0..1. .1..1..0
..1..1..1. .0..0..0. .0..1..0. .0..0..0. .1..0..0. .1..1..0. .0..1..0
..0..0..1. .0..1..1. .0..0..0. .1..1..1. .1..1..1. .0..0..1. .0..1..1
..1..0..0. .0..1..1. .1..1..0. .0..0..1. .1..0..1. .0..0..0. .0..0..0
CROSSREFS
Cf. A300182.
Sequence in context: A108449 A213413 A317512 * A013731 A092811 A363440
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 27 2018
STATUS
approved