A223574 Number of nX6 0..2 arrays with antidiagonals unimodal.
729, 531441, 170772624, 34343644896, 5521860818496, 817235401137408, 120950839368336384, 17900724226513784832, 2649307185524040155136, 392097463457557942960128, 58030424591718575558098944
Offset: 1
Keywords
Examples
Some solutions for n=3 ..0..0..0..2..0..2....0..0..0..0..2..0....0..0..0..0..2..2....0..0..0..0..0..0 ..0..0..0..0..2..2....0..0..0..2..2..2....0..0..1..1..2..2....0..0..1..0..1..1 ..0..0..1..2..1..2....0..0..2..2..1..2....0..0..1..1..1..2....0..0..1..1..0..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,6))^(max(n,6)-min(n,6)+1) * product{ U(i)^2 , i=1..(min(n,6)-1) }
a(n) = 148*a(n-1) for n>5
Comments