A223575 Number of nX7 0..2 arrays with antidiagonals unimodal

2187, 4782969, 3756997728, 1579807665216, 474880030390656, 120950839368336384, 28907250609032395776, 6908832895558742590464, 1651211062038539479120896, 394639443827210935509894144

Offset

1,1

Comments

Column 7 of A223576

Links

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

Formula

Let U(z) = (z^4+6*z^3+23*z^2+18*z+24)/24

a(n) = U(min(n,7))^(max(n,7)-min(n,7)+1) * product{ U(i)^2 , i=1..(min(n,7)-1) }

a(n) = 239*a(n-1) for n>6

Example

Some solutions for n=3
..0..0..0..0..2..1..0....0..0..0..1..1..1..0....0..0..0..0..0..0..1
..0..0..1..0..0..1..1....0..0..0..0..1..2..2....0..0..0..0..1..2..0
..0..0..0..0..1..0..0....0..0..0..1..1..2..1....0..0..0..0..0..2..2

Crossrefs

Sequence in context: A016951 A223794 A223980 * A184693 A017023 A017107

Adjacent sequences: A223572 A223573 A223574 * A223576 A223577 A223578

Keyword

nonn

Author

R. H. Hardin Mar 22 2013

Status

approved