A235730 Number of (n+1)X(2+1) 0..1 arrays with the sum of each 2X2 subblock maximum and minimum lexicographically nondecreasing columnwise and nonincreasing rowwise

58, 380, 2481, 15963, 102683, 659235, 4232565, 27168327, 174393813, 1119403274, 7185285384, 46121125726, 296043902819, 1900256127618, 12197426714764, 78293240150997, 502551211372960, 3225792130564117, 20705819951262020

Offset

1,1

Comments

Column 2 of A235736

Links

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

Formula

Empirical: a(n) = 9*a(n-1) -11*a(n-2) -56*a(n-3) +133*a(n-4) +13*a(n-5) -220*a(n-6) +73*a(n-7) +147*a(n-8) -64*a(n-9) -45*a(n-10) +19*a(n-11) +5*a(n-12) -2*a(n-13)

Example

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

Crossrefs

Sequence in context: A250927 A250920 A235673 * A235443 A235511 A255684

Adjacent sequences: A235727 A235728 A235729 * A235731 A235732 A235733

Keyword

nonn

Author

R. H. Hardin, Jan 15 2014

Status

approved