|
|
A251051
|
|
Number of (n+1)X(4+1) 0..3 arrays with no 2X2 subblock having the sum of its diagonal elements greater than the absolute difference of its antidiagonal elements
|
|
1
|
|
|
2243, 11280, 24893, 59215, 123396, 262200, 533327, 1107413, 2297926, 4888898, 10549941, 23231818, 51804184, 116876925, 265531368, 606511919, 1389607505, 3190603867, 7334375879, 16872832209, 38832132163, 89393731501, 205817073537
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
COMMENTS
|
|
|
LINKS
|
|
|
FORMULA
|
Empirical: a(n) = 8*a(n-1) -25*a(n-2) +35*a(n-3) -7*a(n-4) -49*a(n-5) +77*a(n-6) -55*a(n-7) +20*a(n-8) -3*a(n-9) for n>12
|
|
EXAMPLE
|
Some solutions for n=4
..2..0..0..0..3....2..2..2..2..3....0..1..1..1..3....0..0..0..0..3
..2..0..0..0..3....0..0..0..0..0....0..0..0..0..2....1..0..0..0..2
..2..0..0..0..0....3..3..3..3..3....1..0..0..0..1....2..0..0..0..2
..2..0..0..0..0....0..0..0..0..0....1..0..0..0..1....2..0..0..0..2
..3..1..1..0..0....3..1..1..1..0....2..1..1..1..0....2..0..0..0..1
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|