A184122 Number of nX2 0..3 arrays with rows and columns in nondecreasing order.
10, 86, 561, 2861, 12068, 43947, 142376, 419213, 1139569, 2894178, 6931366, 15770131, 34291532, 71619470, 144269412, 281284873, 532422712, 980922994, 1763049635, 3097467201, 5328692624, 8990408705, 14896447100, 24269860485
Offset: 1
Keywords
Examples
Some solutions for 3X2 ..0..1....2..2....0..1....0..2....0..1....2..3....0..3....0..2....1..2....1..2 ..0..1....2..2....2..0....1..3....3..0....2..3....2..3....1..2....2..0....1..2 ..3..3....2..3....2..2....2..2....3..1....3..1....2..3....2..1....2..3....3..0
Links
- R. H. Hardin, Table of n, a(n) for n = 1..200
Formula
Empirical: a(n)=16*a(n-1)-120*a(n-2)+560*a(n-3)-1820*a(n-4)+4368*a(n-5)-8008*a(n-6)+11440*a(n-7)-12870*a(n-8)+11440*a(n-9)-8008*a(n-10)+4368*a(n-11)-1820*a(n-12)+560*a(n-13)-120*a(n-14)+16*a(n-15)-a(n-16) (=polynomial of degree 15)
Comments