A203725 Number of (n+1)X6 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) nondecreasing in column and row directions, respectively

2278, 12470, 58048, 230014, 808455, 2572189, 7508980, 20395251, 51998196, 125414516, 287825519, 631806642, 1332124235, 2708040628, 5324902859, 10157044643, 18841255222, 34065603378, 60151407191, 103913751089

Offset

1,1

Comments

Column 5 of A203728

Links

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

Formula

Empirical: a(n) = 8*a(n-1) -21*a(n-2) +105*a(n-4) -168*a(n-5) -91*a(n-6) +512*a(n-7) -330*a(n-8) -560*a(n-9) +910*a(n-10) -910*a(n-12) +560*a(n-13) +330*a(n-14) -512*a(n-15) +91*a(n-16) +168*a(n-17) -105*a(n-18) +21*a(n-20) -8*a(n-21) +a(n-22) for n>30

Example

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

Crossrefs

Sequence in context: A195222 A205165 A166222 * A247401 A264256 A236700

Adjacent sequences: A203722 A203723 A203724 * A203726 A203727 A203728

Keyword

nonn

Author

R. H. Hardin Jan 05 2012

Status

approved