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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.
2
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
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 24 2014
STATUS
approved