A236821 Number of (n+1)X(1+1) 0..2 arrays with the maximum plus the minimum minus the lower median of every 2X2 subblock equal

81, 327, 1386, 6093, 27079, 121590, 549173, 2495215, 11389842, 52223381, 240352711, 1110041358, 5141952693, 23882414527, 111181569882, 518644232789, 2423637273943, 11342969544566, 53156257829813, 249385929539023

Offset

1,1

Comments

Column 1 of A236828

Links

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

Formula

Empirical: a(n) = 9*a(n-1) -2*a(n-2) -167*a(n-3) +265*a(n-4) +1110*a(n-5) -2280*a(n-6) -3350*a(n-7) +7924*a(n-8) +4700*a(n-9) -13072*a(n-10) -2560*a(n-11) +9856*a(n-12) +128*a(n-13) -2560*a(n-14)

Example

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

Crossrefs

Sequence in context: A017162 A250427 A236828 * A237511 A237504 A222162

Adjacent sequences: A236818 A236819 A236820 * A236822 A236823 A236824

Keyword

nonn

Author

R. H. Hardin, Jan 31 2014

Status

approved