A184139 Number of nX4 binary arrays with rows and columns in nondecreasing order

5, 25, 130, 650, 2942, 11819, 42305, 136564, 402910, 1099694, 2805530, 6748066, 15412437, 33626131, 70430778, 142218719, 277853339, 526833235, 972034814, 1749218190, 3076360192, 5297051455, 8943742419, 14828643610, 24172697276

Offset

1,1

Comments

Column 4 of A180985

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 degree 15)

Example

Some solutions for 3X4
..0..0..1..1....0..0..0..0....0..1..1..1....0..0..1..1....0..0..0..1
..1..1..0..0....0..0..1..1....1..0..0..1....0..1..0..1....0..0..0..1
..1..1..1..1....1..1..1..1....1..0..1..1....1..1..1..0....0..0..0..1

Crossrefs

Sequence in context: A002002 A182626 A351050 * A102893 A094602 A207834

Adjacent sequences: A184136 A184137 A184138 * A184140 A184141 A184142

Keyword

nonn

Author

R. H. Hardin Jan 09 2011

Status

approved