A250464 Number of (n+1) X (4+1) 0..1 arrays with nondecreasing min(x(i,j),x(i,j-1)) in the i direction and nondecreasing min(x(i,j),x(i-1,j)) in the j direction.

233, 2322, 21753, 204721, 1920345, 18018051, 169000988, 1585251989, 14869200736, 139470660434, 1308202626738, 12270670938062, 115096226185535, 1079578101818582, 10126210672951525, 94981688990498297, 890907882411650813

Offset

1,1

Comments

Column 4 of A250468.

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = 6*a(n-1) +46*a(n-2) -95*a(n-3) -445*a(n-4) +586*a(n-5) +1578*a(n-6) -1665*a(n-7) -2478*a(n-8) +2288*a(n-9) +1812*a(n-10) -1488*a(n-11) -576*a(n-12) +400*a(n-13) +64*a(n-14) -32*a(n-15).

Example

Some solutions for n=3
..0..1..0..0..0....0..0..0..0..1....0..0..1..0..1....0..0..0..0..0
..0..0..0..1..0....1..0..0..0..0....0..0..0..0..1....1..0..1..0..1
..1..0..0..0..1....0..0..1..1..1....0..0..0..0..0....0..1..0..0..0
..0..1..1..1..1....1..0..1..1..1....0..1..0..0..1....1..0..1..1..0

Crossrefs

Cf. A250468.

Sequence in context: A037033 A028474 A101218 * A221812 A219065 A301956

Adjacent sequences: A250461 A250462 A250463 * A250465 A250466 A250467

Keyword

nonn

Author

R. H. Hardin, Nov 23 2014

Status

approved