A299677 Number of nX3 0..1 arrays with every element equal to 0, 1, 2, 4, 5, 6 or 7 king-move adjacent elements, with upper left element zero.

4, 13, 20, 45, 147, 506, 1561, 5017, 16429, 53365, 172859, 562276, 1828820, 5943264, 19318649, 62811656, 204197935, 663816782, 2158064264, 7015860029, 22808258862, 74148897744, 241056311862, 783667226084, 2547678766746, 8282432122501

Offset

1,1

Comments

Column 3 of A299682.

Links

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

Formula

Empirical: a(n) = 4*a(n-1) -2*a(n-2) +4*a(n-3) -16*a(n-4) -13*a(n-5) +12*a(n-6) +40*a(n-7) +23*a(n-8) -37*a(n-9) +15*a(n-10) -88*a(n-11) +52*a(n-12) -48*a(n-13) +49*a(n-14) -8*a(n-15) +20*a(n-16) for n>17

Example

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

Crossrefs

Cf. A299682.

Sequence in context: A299874 A299010 A299801 * A300309 A228138 A339271

Adjacent sequences: A299674 A299675 A299676 * A299678 A299679 A299680

Keyword

nonn

Author

R. H. Hardin, Feb 16 2018

Status

approved