A316125 Number of nX3 0..1 arrays with every element unequal to 1, 2, 3, 5, 6 or 7 king-move adjacent elements, with upper left element zero.

1, 16, 60, 197, 816, 3421, 13488, 54585, 222050, 896928, 3628145, 14702693, 59523873, 240964415, 975799703, 3951226107, 15998479918, 64780965677, 262310632650, 1062132574354, 4300748194584, 17414464996336, 70513993015956

Offset

1,2

Comments

Column 3 of A316130.

Links

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

Formula

Empirical: a(n) = 3*a(n-1) +4*a(n-2) +12*a(n-3) -25*a(n-4) -79*a(n-5) -35*a(n-6) +82*a(n-7) +219*a(n-8) +105*a(n-9) -20*a(n-10) -245*a(n-11) -206*a(n-12) -64*a(n-13) +38*a(n-14) +162*a(n-15) +97*a(n-16) +46*a(n-17) +18*a(n-18) -16*a(n-19) -8*a(n-20) for n>21

Example

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

Crossrefs

Cf. A316130.

Sequence in context: A187173 A296958 A258731 * A345894 A039406 A031190

Adjacent sequences: A316122 A316123 A316124 * A316126 A316127 A316128

Keyword

nonn

Author

R. H. Hardin, Jun 24 2018

Status

approved