|
|
A301779
|
|
Number of nX3 0..1 arrays with every element equal to 0, 1, 2 or 3 horizontally or vertically adjacent elements, with upper left element zero.
|
|
2
|
|
|
4, 32, 240, 1808, 13616, 102544, 772272, 5816080, 43801648, 329875856, 2484337584, 18709866512, 140906415920, 1061184377488, 7991916306096, 60188151652624, 453284726792752, 3413745694159760, 25709358766289328, 193620494140664336
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
COMMENTS
|
|
|
LINKS
|
|
|
FORMULA
|
Empirical: a(n) = 7*a(n-1) +4*a(n-2)
|
|
EXAMPLE
|
Some solutions for n=5
..0..1..0. .0..0..0. .0..0..1. .0..0..1. .0..1..0. .0..1..1. .0..0..1
..1..1..0. .0..1..0. .1..1..1. .0..0..0. .1..1..1. .1..0..0. .0..0..1
..0..0..0. .1..0..1. .0..0..1. .1..1..0. .1..0..0. .0..1..1. .0..0..0
..1..0..1. .1..1..0. .1..1..0. .1..1..1. .0..1..1. .0..1..0. .0..1..0
..0..0..1. .0..0..0. .1..0..1. .1..0..0. .0..0..1. .1..0..0. .1..0..0
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|