A236731 Number of (n+1)X(2+1) 0..2 arrays with the upper median minus the lower median of every 2X2 subblock equal

345, 2471, 17583, 131147, 975553, 7370761, 55873999, 426890075, 3275546533, 25261075001, 195543845671, 1519132794379, 11836226911325, 92460736346337, 723838052083423, 5677220879646115, 44597479303258101, 350802192747968425

Offset

1,1

Comments

Column 2 of A236737

Links

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

Formula

Empirical: a(n) = 20*a(n-1) -103*a(n-2) -358*a(n-3) +4749*a(n-4) -8438*a(n-5) -47573*a(n-6) +201166*a(n-7) -30204*a(n-8) -1074134*a(n-9) +1618940*a(n-10) +1364656*a(n-11) -5060624*a(n-12) +2241312*a(n-13) +4225728*a(n-14) -4631936*a(n-15) +436992*a(n-16) +1161216*a(n-17) -387072*a(n-18) -30720*a(n-19) +16384*a(n-20)

Example

Some solutions for n=4
..0..1..2....1..0..1....0..1..1....1..2..2....1..0..1....0..1..0....1..2..2
..0..0..1....0..0..0....1..2..1....2..0..1....2..2..0....1..1..1....2..1..1
..0..1..2....0..0..0....1..0..1....1..2..0....1..0..1....1..1..1....1..2..2
..0..0..1....0..0..0....0..0..0....0..2..1....2..2..2....0..1..1....2..0..1
..0..1..2....0..1..0....1..0..2....1..0..2....1..0..1....1..2..1....1..0..2

Crossrefs

Sequence in context: A095963 A247079 A333079 * A138043 A048904 A139266

Adjacent sequences: A236728 A236729 A236730 * A236732 A236733 A236734

Keyword

nonn

Author

R. H. Hardin, Jan 30 2014

Status

approved