A303804 Number of nX4 0..1 arrays with every element unequal to 0, 1, 3 or 4 king-move adjacent elements, with upper left element zero.

5, 17, 15, 38, 55, 107, 202, 438, 853, 1858, 3939, 8667, 18603, 41667, 92140, 205636, 455688, 1021747, 2281353, 5111090, 11431713, 25646573, 57451732, 128832642, 288776875, 647818224, 1452633630, 3258392662, 7307981425, 16393919986

Offset

1,1

Comments

Column 4 of A303808.

Links

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

Formula

Empirical: a(n) = 4*a(n-1) -4*a(n-2) -a(n-3) +9*a(n-4) -25*a(n-5) +34*a(n-6) -21*a(n-7) -17*a(n-8) +20*a(n-9) -9*a(n-10) +80*a(n-11) -82*a(n-12) +5*a(n-13) +115*a(n-14) -65*a(n-15) -48*a(n-16) +9*a(n-17) -5*a(n-18) +2*a(n-20) for n>24

Example

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

Crossrefs

Cf. A303808.

Sequence in context: A056850 A302631 A303678 * A304851 A237437 A128895

Adjacent sequences: A303801 A303802 A303803 * A303805 A303806 A303807

Keyword

nonn

Author

R. H. Hardin, Apr 30 2018

Status

approved