A203959 Number of (n+1)X3 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

121, 851, 6586, 45307, 276516, 1512850, 7559349, 35013044, 152204393, 627158203, 2469369220, 9352485042, 34260022340, 121947287786, 423429014908, 1439022449239, 4800503801815, 15758894017829, 51018990415219

Offset

1,1

Comments

Column 2 of A203965

Links

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

Formula

Empirical: a(n) = 22*a(n-1) -218*a(n-2) +1274*a(n-3) -4794*a(n-4) +11682*a(n-5) -16350*a(n-6) +3138*a(n-7) +38004*a(n-8) -79674*a(n-9) +61398*a(n-10) +35118*a(n-11) -127974*a(n-12) +113430*a(n-13) -3210*a(n-14) -85098*a(n-15) +79101*a(n-16) -21204*a(n-17) -17108*a(n-18) +19328*a(n-19) -8656*a(n-20) +1984*a(n-21) -192*a(n-22) for n>25

Example

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

Crossrefs

Sequence in context: A361658 A293588 A365969 * A362319 A211472 A223389

Adjacent sequences: A203956 A203957 A203958 * A203960 A203961 A203962

Keyword

nonn

Author

R. H. Hardin Jan 08 2012

Status

approved