A203958 Number of (n+1) X 2 0..2 arrays with column and row pair sums b(i,j)=a(i,j)+a(i,j-1) and c(i,j)=a(i,j)+a(i-1,j) such that rows of b(i,j) and columns of c(i,j) are lexicographically nondecreasing.

32, 121, 447, 1579, 5352, 17559, 56219, 176797, 548760, 1687165, 5151519, 15651063, 47379056, 143054539, 431129547, 1297582777, 3901661040, 11723857281, 35211417503, 105718138339, 317330575512, 952360824991, 2857854226587

Offset

1,1

Comments

Column 1 of A203965.

Links

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

Formula

Empirical: a(n) = 10*a(n-1) -40*a(n-2) +82*a(n-3) -91*a(n-4) +52*a(n-5) -12*a(n-6).

Empirical g.f.: x*(32 - 199*x + 517*x^2 - 675*x^3 + 432*x^4 - 108*x^5) / ((1 - x)^3*(1 - 2*x)^2*(1 - 3*x)). - Colin Barker, Jun 06 2018

Example

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

Crossrefs

Cf. A203965.

Sequence in context: A297698 A223314 A203965 * A005903 A344219 A271532

Adjacent sequences: A203955 A203956 A203957 * A203959 A203960 A203961

Keyword

nonn

Author

R. H. Hardin, Jan 08 2012

Status

approved