A318547 Number of nX3 0..1 arrays with every element unequal to 1, 2, 4 or 6 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.

1, 6, 5, 21, 44, 106, 258, 600, 1476, 3461, 8382, 19993, 47986, 115062, 275759, 661860, 1587148, 3808959, 9139148, 21934213, 52643142, 126358591, 303319238, 728132846, 1748027976, 4196626333, 10075548717, 24190744152, 58081944604, 139457643789

Offset

1,2

Comments

Column 3 of A318552.

Links

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

Formula

Empirical: a(n) = 6*a(n-2) +10*a(n-3) -4*a(n-4) -39*a(n-5) -51*a(n-6) +7*a(n-7) +78*a(n-8) +78*a(n-9) +a(n-10) -54*a(n-11) -4*a(n-12) +34*a(n-13) +4*a(n-14) -15*a(n-15) -6*a(n-16) +33*a(n-17) +29*a(n-18) -38*a(n-19) -40*a(n-20) +11*a(n-21) +5*a(n-22) +2*a(n-23) -8*a(n-24) -5*a(n-25) +14*a(n-26) -4*a(n-27) -6*a(n-28) +5*a(n-29) +a(n-30) -a(n-31)

Example

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

Crossrefs

Cf. A318552.

Sequence in context: A281175 A281221 A143130 * A082384 A248265 A267284

Adjacent sequences: A318544 A318545 A318546 * A318548 A318549 A318550

Keyword

nonn

Author

R. H. Hardin, Aug 28 2018

Status

approved