|
|
A250687
|
|
Number of (n+1)X(4+1) 0..3 arrays with nondecreasing x(i,j)-x(i,j-1) in the i direction and nondecreasing absolute value of x(i,j)-x(i-1,j) in the j direction
|
|
1
|
|
|
11150, 60508, 324648, 1670016, 8038566, 36673634, 160222342, 676640344, 2784280670, 11235235268, 44688274606, 175922640288, 687672281246, 2676084468860, 10388862354030, 40297745223480, 156374569711646
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
COMMENTS
|
|
|
LINKS
|
|
|
FORMULA
|
Empirical: a(n) = 27*a(n-1) -331*a(n-2) +2439*a(n-3) -12049*a(n-4) +42129*a(n-5) -107225*a(n-6) +201069*a(n-7) -277706*a(n-8) +278928*a(n-9) -197984*a(n-10) +94032*a(n-11) -26784*a(n-12) +3456*a(n-13) for n>17
|
|
EXAMPLE
|
Some solutions for n=2
..3..2..1..0..0....0..3..2..0..0....1..2..0..2..2....3..2..1..0..0
..3..2..1..1..1....0..3..2..0..2....1..3..1..3..3....3..3..2..1..1
..3..3..3..3..3....0..3..2..0..2....1..3..1..3..3....3..3..3..2..2
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|