login
A305036
Number of nX4 0..1 arrays with every element unequal to 0, 1, 2, 6 or 7 king-move adjacent elements, with upper left element zero.
1
8, 5, 7, 19, 26, 61, 143, 277, 568, 1244, 2600, 5369, 11341, 23905, 49970, 104796, 220286, 462165, 969275, 2034517, 4270128, 8959604, 18801136, 39456489, 82798877, 173748993, 364613994, 765145940, 1605646822, 3369435285, 7070757515
OFFSET
1,1
COMMENTS
Column 4 of A305040.
LINKS
FORMULA
Empirical: a(n) = a(n-1) +5*a(n-3) +a(n-4) -4*a(n-6) -4*a(n-7) for n>11
EXAMPLE
Some solutions for n=5
..0..0..0..0. .0..0..0..0. .0..1..1..1. .0..0..0..0. .0..0..0..1
..0..0..1..0. .0..0..0..0. .1..0..1..1. .0..1..1..0. .0..0..1..0
..0..0..1..0. .0..1..1..0. .1..1..0..1. .0..0..0..0. .0..0..0..0
..0..0..0..0. .0..0..0..0. .1..1..1..1. .0..0..0..0. .0..0..0..0
..0..0..0..0. .0..0..0..0. .1..1..1..1. .0..0..0..0. .0..0..0..0
CROSSREFS
Cf. A305040.
Sequence in context: A265303 A021925 A227514 * A357106 A119812 A153799
KEYWORD
nonn
AUTHOR
R. H. Hardin, May 24 2018
STATUS
approved