A229418 Number of 4X4 0..n zero-diagonal arrays with corresponding row and column sums equal

152, 4743, 59008, 426425, 2164680, 8583967, 28371968, 81545697, 209841400, 493679879, 1078445952, 2213497273, 4308069416, 8009070975, 14306664448, 24674505857, 41252568408, 67081603015, 106399491200, 165011023737

Offset

1,1

Comments

Row 4 of A229417

Links

Table of n, a(n) for n=1..20.

Formula

Empirical: a(n) = (29/140)*n^9 + (261/140)*n^8 + (811/105)*n^7 + (289/15)*n^6 + (1921/60)*n^5 + (2221/60)*n^4 + (6323/210)*n^3 + (3539/210)*n^2 + (208/35)*n + 1

Example

Some solutions for n=4
..0..1..1..4....0..1..1..4....0..0..2..4....0..0..1..3....0..1..2..3
..0..0..1..2....4..0..1..3....0..0..3..1....1..0..2..2....2..0..3..2
..2..0..0..1....2..3..0..0....4..0..0..1....0..3..0..2....1..4..0..3
..4..2..1..0....0..4..3..0....2..4..0..0....3..2..2..0....3..2..3..0

Crossrefs

Sequence in context: A359447 A223397 A239065 * A035823 A265861 A208484

Adjacent sequences: A229415 A229416 A229417 * A229419 A229420 A229421

Keyword

nonn

Author

R. H. Hardin Sep 22 2013

Status

approved