|
|
A305447
|
|
Number of nX3 0..1 arrays with every element unequal to 1, 2, 4, 5 or 8 king-move adjacent elements, with upper left element zero.
|
|
1
|
|
|
1, 11, 7, 20, 44, 77, 181, 379, 849, 1799, 4154, 9242, 20384, 46987, 105477, 238364, 544013, 1234035, 2805803, 6392808, 14558529, 33157368, 75581441, 172296118, 392727236, 895513084, 2042029380, 4656342833, 10619040244, 24217647660
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,2
|
|
COMMENTS
|
|
|
LINKS
|
|
|
FORMULA
|
Empirical: a(n) = a(n-1) +3*a(n-2) +7*a(n-3) -6*a(n-4) -18*a(n-5) -26*a(n-6) +8*a(n-7) +27*a(n-8) +47*a(n-9) +16*a(n-10) -5*a(n-11) -3*a(n-12) -7*a(n-13) -20*a(n-14) -24*a(n-15) -5*a(n-16) -6*a(n-17) for n>18
|
|
EXAMPLE
|
Some solutions for n=5
..0..0..1. .0..1..0. .0..0..0. .0..0..0. .0..1..0. .0..0..0. .0..0..0
..1..1..1. .0..0..0. .0..1..0. .1..0..1. .0..0..1. .0..1..0. .0..1..0
..1..1..1. .0..0..0. .0..0..0. .0..0..0. .0..0..0. .0..0..0. .0..0..0
..0..1..0. .1..0..1. .0..0..0. .0..0..0. .0..1..0. .0..0..0. .0..1..0
..1..1..1. .0..0..0. .0..1..1. .1..1..0. .0..0..0. .0..1..0. .0..0..0
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|