A183410 Number of nX3 binary arrays with each sum of a(1..i,1..j) no greater than i*j/2 and rows and columns in nondecreasing order

2, 8, 22, 75, 152, 410, 719, 1632, 2564, 5130, 7525, 13720, 19058, 32359, 43246, 69423, 89870, 137872, 174193, 257432, 318491, 456159, 554945, 773911, 927617, 1264264, 1496874, 1999757, 2341547, 3073792, 3565513, 4608374, 5299770, 6755665, 7711920

Offset

1,1

Comments

Column 3 of A183413

Links

R. H. Hardin, Table of n, a(n) for n = 1..200

Formula

Empirical: a(n)=a(n-1)+2*a(n-4)-2*a(n-5)+a(n-6)-a(n-7)+3*a(n-8)-3*a(n-9)-2*a(n-10)+2*a(n-11)-8*a(n-12)+8*a(n-13)-3*a(n-14)+3*a(n-15)-2*a(n-16)+2*a(n-17)+8*a(n-18)-8*a(n-19)+12*a(n-20)-12*a(n-21)+2*a(n-22)-2*a(n-23)-2*a(n-24)+2*a(n-25)-12*a(n-26)+12*a(n-27)-8*a(n-28)+8*a(n-29)+2*a(n-30)-2*a(n-31)+3*a(n-32)-3*a(n-33)+8*a(n-34)-8*a(n-35)+2*a(n-36)-2*a(n-37)-3*a(n-38)+3*a(n-39)-a(n-40)+a(n-41)-2*a(n-42)+2*a(n-43)+a(n-46)-a(n-47)

Example

Some solutions for 4X3
..0..0..1....0..0..1....0..0..1....0..0..1....0..0..0....0..0..1....0..0..1
..0..0..1....0..0..1....0..0..1....0..1..1....0..0..0....0..1..0....0..0..1
..0..1..1....0..1..0....0..1..0....1..0..0....0..1..1....0..1..0....0..1..1
..0..1..1....1..0..1....1..1..0....1..0..1....1..1..1....1..1..0....1..0..1

Crossrefs

Sequence in context: A045695 A106053 A121135 * A072929 A328140 A053958

Adjacent sequences: A183407 A183408 A183409 * A183411 A183412 A183413

Keyword

nonn

Author

R. H. Hardin Jan 04 2011

Status

approved