|
| |
|
|
A305218
|
|
Number of nX3 0..1 arrays with every element unequal to 2, 3, 5, 6 or 7 king-move adjacent elements, with upper left element zero.
|
|
2
|
|
|
|
0, 4, 8, 15, 31, 92, 264, 784, 2378, 7342, 22596, 69617, 214983, 664217, 2052307, 6342935, 19606074, 60603932, 187335711, 579091828, 1790098137, 5533594957, 17105617402, 52877461311, 163456660240, 505283076436, 1561949355656
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
|
OFFSET
|
1,2
|
|
|
COMMENTS
|
|
|
|
LINKS
|
|
|
|
FORMULA
|
Empirical: a(n) = 2*a(n-1) +5*a(n-2) -12*a(n-4) -15*a(n-5) +3*a(n-6) +30*a(n-7) +14*a(n-8) -40*a(n-9) -44*a(n-10) +23*a(n-11) +66*a(n-12) +22*a(n-13) -15*a(n-14) -6*a(n-15) for n>18
|
|
|
EXAMPLE
|
Some solutions for n=5
..0..0..1. .0..1..0. .0..1..0. .0..1..0. .0..1..0. .0..1..0. .0..1..0
..1..1..0. .1..1..1. .1..1..0. .1..1..0. .1..0..1. .1..1..0. .1..1..1
..1..0..0. .1..0..1. .0..0..1. .0..0..1. .1..0..1. .1..0..0. .1..0..1
..0..1..1. .1..0..1. .0..1..1. .0..1..1. .1..0..1. .0..1..1. .0..0..1
..0..1..0. .0..1..0. .1..0..0. .0..1..0. .0..1..0. .0..1..0. .1..1..0
|
|
|
CROSSREFS
|
|
|
|
KEYWORD
|
nonn
|
|
|
AUTHOR
|
|
|
|
STATUS
|
approved
|
| |
|
|
