login
A283629
Number of nX3 0..1 arrays with no 1 equal to more than one of its horizontal, diagonal and antidiagonal neighbors, with the exception of exactly two elements.
1
0, 0, 37, 388, 3729, 28828, 203025, 1325980, 8216341, 48912768, 282293033, 1589466368, 8771503165, 47606031352, 254776347029, 1347286728096, 7051427209337, 36575153581764, 188217385278837, 961810924181084
OFFSET
1,3
COMMENTS
Column 3 of A283634.
LINKS
FORMULA
Empirical: a(n) = 15*a(n-1) -78*a(n-2) +134*a(n-3) +162*a(n-4) -840*a(n-5) +728*a(n-6) +1398*a(n-7) -3117*a(n-8) +413*a(n-9) +4626*a(n-10) -4056*a(n-11) -2576*a(n-12) +5376*a(n-13) -768*a(n-14) -3200*a(n-15) +1536*a(n-16) +768*a(n-17) -512*a(n-18)
EXAMPLE
Some solutions for n=4
..1..1..1. .0..1..0. .0..1..0. .0..1..1. .1..1..1. .0..0..0. .0..1..0
..1..0..0. .0..1..1. .1..1..0. .0..0..1. .0..0..1. .1..0..0. .1..0..0
..0..0..0. .0..0..1. .0..1..0. .1..0..1. .1..0..0. .0..1..0. .1..1..1
..1..1..1. .1..0..0. .1..0..0. .1..1..0. .1..1..0. .0..1..1. .0..0..0
CROSSREFS
Cf. A283634.
Sequence in context: A178613 A124337 A027944 * A349742 A264626 A201789
KEYWORD
nonn
AUTHOR
R. H. Hardin, Mar 12 2017
STATUS
approved