A236721 Number of (n+1)X(1+1) 0..2 arrays with the maximum plus the upper median plus the lower median minus the minimum of every 2X2 subblock equal

81, 211, 550, 1517, 4227, 12072, 34817, 101881, 300694, 896941, 2695583, 8170608, 24926541, 76581709, 236571526, 735006969, 2293934715, 7192276024, 22632537625, 71477629985, 226390525302, 719056784565, 2288987001383, 7302243641824

Offset

1,1

Comments

Column 1 of A236728

Links

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

Formula

Empirical: a(n) = 7*a(n-1) +12*a(n-2) -177*a(n-3) +89*a(n-4) +1806*a(n-5) -2318*a(n-6) -9698*a(n-7) +16880*a(n-8) +30048*a(n-9) -63832*a(n-10) -54640*a(n-11) +140752*a(n-12) +54864*a(n-13) -184064*a(n-14) -22784*a(n-15) +135936*a(n-16) -4480*a(n-17) -48640*a(n-18) +5120*a(n-19) +5120*a(n-20)

Example

Some solutions for n=7
..0..1....0..1....1..1....2..0....1..0....1..0....0..0....0..1....1..0....1..1
..1..2....2..1....0..2....0..2....1..1....2..1....1..2....1..1....2..1....1..2
..2..1....1..2....0..2....1..1....1..0....1..2....0..0....2..1....1..2....0..0
..2..1....2..1....1..1....2..0....0..2....2..1....1..2....1..1....1..2....1..2
..1..2....2..1....2..0....2..0....0..1....2..1....0..0....1..0....1..2....0..0
..1..2....0..1....2..0....1..1....1..1....2..1....2..1....2..0....0..1....2..1
..2..1....1..2....1..1....2..0....0..1....1..2....1..1....0..1....2..1....0..0
..0..1....0..1....2..2....2..0....1..1....0..1....2..1....1..1....0..1....1..2

Crossrefs

Sequence in context: A236884 A236728 A236877 * A255110 A062532 A075730

Adjacent sequences: A236718 A236719 A236720 * A236722 A236723 A236724

Keyword

nonn

Author

R. H. Hardin, Jan 30 2014

Status

approved