A223575 Number of nX7 0..2 arrays with antidiagonals unimodal.
2187, 4782969, 3756997728, 1579807665216, 474880030390656, 120950839368336384, 28907250609032395776, 6908832895558742590464, 1651211062038539479120896, 394639443827210935509894144
Offset: 1
Keywords
Examples
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
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
Comments