|
|
A302636
|
|
Number of 3Xn 0..1 arrays with every element equal to 0, 1, 3 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.
|
|
1
|
|
|
4, 6, 8, 14, 25, 47, 83, 150, 269, 488, 876, 1581, 2845, 5133, 9242, 16661, 30012, 54094, 97457, 175631, 316451, 570258, 1027529, 1851592, 3336392, 6012049, 10833241, 19520945, 35175378, 63384029, 114213840, 205806518, 370850169, 668249367
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
COMMENTS
|
|
|
LINKS
|
|
|
FORMULA
|
Empirical: a(n) = a(n-1) +a(n-2) +2*a(n-4) -a(n-5) for n>7
|
|
EXAMPLE
|
Some solutions for n=5
..0..1..0..1..0. .0..1..0..1..0. .0..1..0..1..0. .0..1..0..1..0
..0..1..0..0..1. .0..1..0..1..0. .0..1..0..1..1. .1..0..0..1..0
..0..0..1..0..1. .0..0..1..1..0. .1..0..0..1..0. .1..0..1..0..0
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|