A250449 Number of (n+1)X(3+1) 0..2 arrays with nondecreasing min(x(i,j),x(i,j-1)) in the i direction and nondecreasing min(x(i,j),x(i-1,j)) in the j direction

1000, 17024, 258377, 3865967, 56575618, 822755006, 11894220206, 171683275444, 2474382329697, 35650926095264, 513470954639266, 7395025073096956, 106494006557989138, 1533588742446599887, 22084284507852882601

Offset

1,1

Comments

Column 3 of A250454

Links

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

Formula

Empirical: a(n) = 15*a(n-1) +90*a(n-2) -1507*a(n-3) -1884*a(n-4) +46515*a(n-5) +26122*a(n-6) -672221*a(n-7) -348239*a(n-8) +5134194*a(n-9) +2711324*a(n-10) -22852812*a(n-11) -11566900*a(n-12) +63118584*a(n-13) +28521664*a(n-14) -111737504*a(n-15) -42111776*a(n-16) +127619328*a(n-17) +37466560*a(n-18) -92247040*a(n-19) -19578368*a(n-20) +40071168*a(n-21) +5544960*a(n-22) -9363456*a(n-23) -663552*a(n-24) +884736*a(n-25)

Example

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

Crossrefs

Sequence in context: A161770 A004632 A277397 * A117690 A186936 A185747

Adjacent sequences: A250446 A250447 A250448 * A250450 A250451 A250452

Keyword

nonn

Author

R. H. Hardin, Nov 23 2014

Status

approved