|
|
A303406
|
|
Number of nX3 0..1 arrays with every element equal to 1, 2, 4, 5 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.
|
|
1
|
|
|
1, 7, 28, 119, 541, 2327, 10384, 47491, 208616, 938105, 4229023, 18855226, 84609455, 379973132, 1700940358, 7627893865, 34215621269, 153337948168, 687522535009, 3082887354405, 13820286385598, 61963243406462, 277818915171978
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,2
|
|
COMMENTS
|
|
|
LINKS
|
|
|
FORMULA
|
Empirical: a(n) = 2*a(n-1) +7*a(n-2) +35*a(n-3) -36*a(n-4) -151*a(n-5) -97*a(n-6) +34*a(n-7) +258*a(n-8) -724*a(n-9) +256*a(n-10) +1584*a(n-11) -240*a(n-12) -512*a(n-13) -304*a(n-14) +1728*a(n-15) -1344*a(n-16) -1792*a(n-17) +1024*a(n-18)
|
|
EXAMPLE
|
Some solutions for n=5
..0..1..1. .0..1..0. .0..1..0. .0..0..0. .0..1..0. .0..0..1. .0..0..0
..1..0..0. .0..0..1. .1..0..1. .0..1..0. .0..0..1. .0..1..1. .1..0..1
..1..0..1. .0..0..0. .0..1..0. .1..0..0. .1..0..0. .0..1..0. .0..1..0
..1..1..1. .1..1..0. .1..0..1. .1..1..0. .1..1..1. .0..0..0. .1..0..1
..0..0..0. .0..0..1. .1..1..1. .1..0..1. .0..0..1. .0..0..0. .0..0..0
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|