A223570 Number of n X n 0..2 arrays with antidiagonals unimodal.
3, 81, 16038, 16230456, 64207683936, 817235401137408, 28907250609032395776, 2535541672670058530700288, 503424192483622111094950081536, 209983768351036102380925723459562496
Offset: 1
Keywords
Examples
Some solutions for n=3 ..1..0..2....0..2..1....2..1..2....1..0..2....0..0..0....1..2..0....0..0..0 ..1..1..2....1..1..1....2..2..0....1..0..1....0..1..0....0..1..0....1..0..2 ..1..1..0....0..0..0....2..1..1....0..1..2....1..1..1....2..0..0....0..0..0
Links
- R. H. Hardin, Table of n, a(n) for n = 1..64
Formula
Let U(z) = (z^4+6*z^3+23*z^2+18*z+24)/24
a(n) = U(n) * product{ U(i)^2 , i=1..(n-1) }
Comments