A305178 Number of n X 4 0..1 arrays with every element unequal to 1, 2, 5, 6 or 7 king-move adjacent elements, with upper left element zero.

2, 1, 9, 10, 13, 47, 71, 118, 241, 453, 870, 1608, 3110, 6075, 11491, 22105, 42831, 82321, 158514, 305836, 589983, 1137829, 2194384, 4234349, 8170446, 15762684, 30415495, 58692610, 113253536, 218539740, 421716458, 813790085, 1570376360

Offset

1,1

Comments

Column 4 of A305182.

Links

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

Formula

Empirical: a(n) = a(n-1) +a(n-2) +3*a(n-3) -2*a(n-5) -5*a(n-6) -3*a(n-7) -2*a(n-9) +a(n-10) +2*a(n-11) for n>18.

Example

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

Crossrefs

Cf. A305182.

Sequence in context: A132744 A059604 A048160 * A295851 A368375 A192324

Adjacent sequences: A305175 A305176 A305177 * A305179 A305180 A305181

Keyword

nonn

Author

R. H. Hardin, May 26 2018

Status

approved