A250945 Number of (3+1)X(n+1) 0..2 arrays with nondecreasing x(i,j)+x(i,j-1) in the i direction and nondecreasing absolute value of x(i,j)-x(i-1,j) in the j direction

413, 2812, 16208, 87529, 442409, 2130148, 9865706, 44282475, 193738371, 829672404, 3489686970, 14454185655, 59084278573, 238768911154, 955319655916, 3788887514683, 14911360133421, 58283593894282, 226427164514046

Offset

1,1

Comments

Row 3 of A250942

Links

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

Formula

Empirical: a(n) = 12*a(n-1) -38*a(n-2) -76*a(n-3) +619*a(n-4) -500*a(n-5) -2802*a(n-6) +4652*a(n-7) +5756*a(n-8) -14556*a(n-9) -5630*a(n-10) +24440*a(n-11) +1511*a(n-12) -24616*a(n-13) +1882*a(n-14) +15280*a(n-15) -1829*a(n-16) -5700*a(n-17) +596*a(n-18) +1160*a(n-19) -64*a(n-20) -96*a(n-21)

Example

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

Crossrefs

Sequence in context: A250901 A205755 A331825 * A205585 A176381 A027661

Adjacent sequences: A250942 A250943 A250944 * A250946 A250947 A250948

Keyword

nonn

Author

R. H. Hardin, Nov 28 2014

Status

approved