A203724 Number of (n+1)X5 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

888, 4737, 20290, 72777, 230014, 656441, 1728140, 4246268, 9847415, 21700159, 45744109, 92663818, 181178545, 343044939, 630954514, 1130114352, 1975727787, 3377874220, 5657695118, 9297612083, 15012132902, 23843994305, 37296211132

Offset

1,1

Comments

Column 4 of A203728

Links

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

Formula

Empirical: a(n) = 9*a(n-1) -30*a(n-2) +30*a(n-3) +75*a(n-4) -243*a(n-5) +152*a(n-6) +360*a(n-7) -690*a(n-8) +130*a(n-9) +780*a(n-10) -780*a(n-11) -130*a(n-12) +690*a(n-13) -360*a(n-14) -152*a(n-15) +243*a(n-16) -75*a(n-17) -30*a(n-18) +30*a(n-19) -9*a(n-20) +a(n-21) for n>26

Example

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

Crossrefs

Sequence in context: A043523 A066270 A236981 * A006915 A178270 A183751

Adjacent sequences: A203721 A203722 A203723 * A203725 A203726 A203727

Keyword

nonn

Author

R. H. Hardin Jan 05 2012

Status

approved