A235502 Number of (n+1)X(1+1) 0..3 arrays with the sum of each 2X2 subblock maximum and minimum lexicographically nondecreasing rowwise and columnwise

256, 2982, 33640, 343500, 3415268, 32611962, 306033109, 2817787860, 25672159052, 231626605740, 2076931776520, 18526379447880, 164667929387896, 1459450648692460, 12908951676356545, 114001890051039912

Offset

1,1

Comments

Column 1 of A235506

Links

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

Formula

Empirical: a(n) = 16*a(n-1) -996*a(n-3) +2120*a(n-4) +25116*a(n-5) -57572*a(n-6) -356724*a(n-7) +603662*a(n-8) +3113580*a(n-9) -2452580*a(n-10) -15915180*a(n-11) -310416*a(n-12) +41666900*a(n-13) +22553332*a(n-14) -51946236*a(n-15) -50892645*a(n-16) +22355988*a(n-17) +43357140*a(n-18) +7658496*a(n-19) -11766240*a(n-20) -6600960*a(n-21) -1036800*a(n-22)

Example

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

Crossrefs

Sequence in context: A236139 A235747 A235506 * A236202 A236199 A188823

Adjacent sequences: A235499 A235500 A235501 * A235503 A235504 A235505

Keyword

nonn

Author

R. H. Hardin, Jan 11 2014

Status

approved