A226987 Number of n X n 0..4 arrays of sums of 2X2 subblocks of some (n+1)X(n+1) binary array with rows and columns of the latter in lexicographically nondecreasing order

5, 42, 608, 24158, 2601925, 833294380, 816606210291, 2510846575278844

Offset

1,1

Comments

Diagonal of A226992

Links

Table of n, a(n) for n=1..8.

Example

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

Crossrefs

Sequence in context: A323313 A363435 A337593 * A336605 A204235 A188405

Adjacent sequences: A226984 A226985 A226986 * A226988 A226989 A226990

Keyword

nonn

Author

R. H. Hardin Jun 25 2013

Status

approved