A250530 Number of (n+1)X(2+1) 0..3 arrays with nondecreasing max(x(i,j),x(i,j-1)) in the i direction and nondecreasing min(x(i,j),x(i-1,j)) in the j direction

700, 6012, 44017, 289035, 1767743, 10248336, 57297797, 311492811, 1660155153, 8712978900, 45218940684, 232652531053, 1189341514559, 6050012100793, 30661998107606, 154958014837147, 781456621840360, 3934524933037624

Offset

1,1

Comments

Column 2 of A250536

Links

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

Formula

Empirical: a(n) = 19*a(n-1) -126*a(n-2) +183*a(n-3) +1796*a(n-4) -8913*a(n-5) +4573*a(n-6) +66844*a(n-7) -159500*a(n-8) -110347*a(n-9) +880170*a(n-10) -671453*a(n-11) -2023137*a(n-12) +3717534*a(n-13) +1245646*a(n-14) -7902628*a(n-15) +3640217*a(n-16) +8175766*a(n-17) -8942921*a(n-18) -2871444*a(n-19) +8558015*a(n-20) -2088628*a(n-21) -3791479*a(n-22) +2465772*a(n-23) +449922*a(n-24) -865945*a(n-25) +183465*a(n-26) +86000*a(n-27) -45400*a(n-28) +6000*a(n-29)

Example

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

Crossrefs

Sequence in context: A293203 A157366 A293279 * A200169 A093270 A093235

Adjacent sequences: A250527 A250528 A250529 * A250531 A250532 A250533

Keyword

nonn

Author

R. H. Hardin, Nov 24 2014

Status

approved