|
|
A318541
|
|
Number of nX4 0..1 arrays with every element unequal to 0, 1, 4 or 6 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.
|
|
1
|
|
|
5, 5, 13, 31, 78, 207, 516, 1288, 3270, 8271, 20866, 52679, 133064, 336062, 848616, 2143101, 5412264, 13667874, 34516655, 87168177, 220132818, 555919912, 1403912579, 3545419471, 8953548234, 22611157039, 57101877461, 144204222586
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
COMMENTS
|
|
|
LINKS
|
|
|
FORMULA
|
Empirical: a(n) = a(n-1) +7*a(n-3) +3*a(n-4) +10*a(n-5) -a(n-6) +4*a(n-7) -6*a(n-8) -a(n-9) -a(n-10) -a(n-12) +a(n-13) for n>14
|
|
EXAMPLE
|
Some solutions for n=5
..0..1..0..0. .0..0..0..0. .0..0..0..0. .0..0..0..0. .0..1..0..0
..0..0..0..1. .1..0..0..1. .0..0..0..0. .0..0..0..0. .0..0..0..0
..0..0..0..0. .0..0..0..0. .0..0..0..0. .0..0..0..1. .0..0..0..0
..0..0..0..0. .0..0..0..0. .0..1..0..0. .1..0..0..0. .0..0..0..0
..0..0..0..0. .0..0..1..0. .0..0..0..0. .0..0..0..0. .0..1..0..0
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|