A303686 Number of nX4 0..1 arrays with every element unequal to 2, 3 or 4 king-move adjacent elements, with upper left element zero.

0, 18, 20, 138, 343, 1744, 5563, 23963, 85439, 343499, 1279385, 5002512, 18966028, 73327791, 280007343, 1077678731, 4127070788, 15855095931, 60788926535, 233363355500, 895138948721, 3435345789704, 13179822216490, 50575246236646

Offset

1,2

Comments

Column 4 of A303690.

Links

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

Formula

Empirical: a(n) = a(n-1) +16*a(n-2) -80*a(n-4) -37*a(n-5) +195*a(n-6) +139*a(n-7) -235*a(n-8) -254*a(n-9) +22*a(n-10) +175*a(n-11) +412*a(n-12) +300*a(n-13) -564*a(n-14) -853*a(n-15) +201*a(n-16) +822*a(n-17) +70*a(n-18) -251*a(n-19) +26*a(n-20) -139*a(n-21) -266*a(n-22) +225*a(n-23) +290*a(n-24) -140*a(n-25) -150*a(n-26) +24*a(n-27) +78*a(n-28) -16*a(n-29) -14*a(n-30) +4*a(n-31) for n>35

Example

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

Crossrefs

Cf. A303690.

Sequence in context: A182226 A066240 A115747 * A185099 A216295 A217058

Adjacent sequences: A303683 A303684 A303685 * A303687 A303688 A303689

Keyword

nonn

Author

R. H. Hardin, Apr 28 2018

Status

approved