A250739 Number of (n+1) X (5+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.

66, 70, 78, 94, 126, 190, 318, 574, 1086, 2110, 4158, 8254, 16446, 32830, 65598, 131134, 262206, 524350, 1048638, 2097214, 4194366, 8388670, 16777278, 33554494, 67108926, 134217790, 268435518, 536870974, 1073741886, 2147483710, 4294967358

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) + 62.

Empirical g.f.: 2*x*(33 - 64*x) / ((1 - x)*(1 - 2*x)). - Colin Barker, Nov 17 2018

Example

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

Crossrefs

Column 5 of A250742.

Sequence in context: A059175 A031960 A181464 * A124142 A036207 A039538

Adjacent sequences: A250736 A250737 A250738 * A250740 A250741 A250742

Keyword

nonn

Author

R. H. Hardin, Nov 27 2014

Status

approved