A235527 Number of (n+1)X(1+1) 0..2 arrays with the sum of each 2X2 subblock two median terms lexicographically nondecreasing rowwise and columnwise

81, 498, 2996, 15782, 80584, 388008, 1819537, 8271237, 36871545, 161304512, 695920632, 2965654390, 12514374020, 52363323354, 217577519113, 898716211257, 3693767937225, 15117615578422, 61652409218404, 250671974396430

Offset

1,1

Comments

Column 1 of A235531

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = 10*a(n-1) -10*a(n-2) -182*a(n-3) +432*a(n-4) +1446*a(n-5) -4430*a(n-6) -6826*a(n-7) +23217*a(n-8) +22320*a(n-9) -70888*a(n-10) -54080*a(n-11) +126752*a(n-12) +91840*a(n-13) -121152*a(n-14) -91392*a(n-15) +46080*a(n-16) +36864*a(n-17)

Example

Some solutions for n=5
..1..0....1..1....0..1....0..0....1..1....1..1....0..2....1..2....1..0....2..0
..0..1....1..0....2..0....1..0....2..1....0..0....1..0....1..1....1..0....1..0
..1..0....1..1....2..0....2..1....1..1....2..1....1..0....2..0....0..2....2..0
..2..0....2..0....2..1....0..2....0..1....0..1....2..0....0..2....0..2....1..1
..1..1....0..2....1..2....1..2....1..2....1..2....0..1....2..0....2..1....0..2
..1..1....1..1....2..0....2..1....2..2....0..2....0..1....0..2....2..0....2..0

Crossrefs

Sequence in context: A205057 A235756 A235531 * A297122 A128912 A076090

Adjacent sequences: A235524 A235525 A235526 * A235528 A235529 A235530

Keyword

nonn

Author

R. H. Hardin, Jan 11 2014

Status

approved