A250740 Number of (n+1) X (6+1) 0..1 arrays with nondecreasing x(i,j)-x(i,j-1) in the i direction and nonincreasing x(i,j)-x(i-1,j) in the j direction.

130, 134, 142, 158, 190, 254, 382, 638, 1150, 2174, 4222, 8318, 16510, 32894, 65662, 131198, 262270, 524414, 1048702, 2097278, 4194430, 8388734, 16777342, 33554558, 67108990, 134217854, 268435582, 536871038, 1073741950, 2147483774, 4294967422

Offset

1,1

Links

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

Formula

Empirical: a(n) = 3*a(n-1) - 2*a(n-2); a(n) = 2^(n+1) + 126.

Empirical g.f.: 2*x*(65 - 128*x) / ((1 - x)*(1 - 2*x)). - Colin Barker, Nov 17 2018

Example

Some solutions for n=4:
..0..0..0..0..0..0..0....0..1..1..1..0..0..0....0..1..1..0..0..0..1
..0..0..0..0..0..0..0....0..1..1..1..0..0..0....0..1..1..0..0..0..1
..0..0..0..0..0..0..0....0..1..1..1..0..0..0....0..1..1..0..0..0..1
..1..1..1..1..1..1..1....0..1..1..1..0..0..0....0..1..1..0..0..0..1
..1..1..1..1..1..1..1....0..1..1..1..0..0..0....0..1..1..0..0..0..1

Crossrefs

Column 6 of A250742.

Sequence in context: A298726 A299560 A043604 * A025372 A045049 A163555

Adjacent sequences: A250737 A250738 A250739 * A250741 A250742 A250743

Keyword

nonn

Author

R. H. Hardin, Nov 27 2014

Status

approved