A237385 Number of (n+1)X(1+1) 0..2 arrays colored with the maximum plus the upper median minus the minimum of every 2X2 subblock.

81, 434, 2336, 12624, 68064, 366568, 1976940, 10657560, 57441532, 309578264, 1668794652, 8995139000, 48484851148, 261335232440, 1408647749404, 7592807398296, 40926289471308, 220597727495896, 1189054017281884

Offset: 1

Author

R. H. Hardin, Feb 07 2014

Keywords

• nonn

Comments

Column 1 of A237391

Examples

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

Links

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

Formula

Empirical: a(n) = 30*a(n-3) +349*a(n-4) +818*a(n-5) +3504*a(n-6) +7320*a(n-7) +9876*a(n-8) +18056*a(n-9) -14960*a(n-10) -63872*a(n-11) -133008*a(n-12) -307168*a(n-13) -194624*a(n-14) +71296*a(n-15) +344832*a(n-16) +1077248*a(n-17) +985088*a(n-18) -16384*a(n-19) -212992*a(n-20)