A250634 Number of (2+1)X(n+1) 0..2 arrays with nondecreasing 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

125, 654, 2969, 12360, 49310, 190213, 720347, 2690076, 9964237, 36686400, 134581437, 492406440, 1798700175, 6562904559, 23928907661, 87203461550, 317693877115, 1157153380541, 4214191335186, 15346090893547, 55879956700824

Offset

1,1

Comments

Row 2 of A250632

Links

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

Formula

Empirical: a(n) = 9*a(n-1) -21*a(n-2) -32*a(n-3) +195*a(n-4) -160*a(n-5) -371*a(n-6) +679*a(n-7) +5*a(n-8) -716*a(n-9) +413*a(n-10) +152*a(n-11) -200*a(n-12) +48*a(n-13) for n>16

Example

Some solutions for n=4
..0..0..0..0..2....0..0..0..2..1....0..0..0..1..1....0..0..0..0..0
..0..0..0..1..1....0..0..1..1..2....0..0..1..1..2....0..1..0..0..1
..0..0..0..1..1....1..2..1..2..2....2..2..0..2..1....1..0..2..1..0

Crossrefs

Sequence in context: A211176 A045170 A235896 * A250944 A251288 A060093

Adjacent sequences: A250631 A250632 A250633 * A250635 A250636 A250637

Keyword

nonn

Author

R. H. Hardin, Nov 26 2014

Status

approved