A252923 Number of n X n nonnegative integer arrays with upper left 0 and lower right n+n-6 and value increasing by 0 or 1 with every step right or down.

0, 0, 1, 615, 84910, 8241540, 759337545, 73117894428, 7578889491370, 848729993032718, 102072779621746876, 13069744040275286234, 1766655687081261435255, 250232365919081938956865, 36910187948533534644694094

Offset

1,4

Links

Alois P. Heinz, Table of n, a(n) for n = 1..20 (first 15 terms from R. H. Hardin)

Example

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

Crossrefs

Diagonal of A252930.

Sequence in context: A210103 A191938 A195809 * A268245 A268102 A190029

Adjacent sequences: A252920 A252921 A252922 * A252924 A252925 A252926

Keyword

nonn

Author

R. H. Hardin, Dec 24 2014

Status

approved