A250997 Number of (3+1)X(n+1) 0..2 arrays with nondecreasing min(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

612, 4111, 21955, 104674, 456514, 1869400, 7290819, 27384143, 99810933, 355081380, 1238282515, 4247230905, 14365389147, 48012656399, 158834880759, 520810627308, 1694515771864, 5475830857755, 17588753976895, 56194112675498

Offset

1,1

Comments

Row 3 of A250994

Links

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

Formula

Empirical: a(n) = 10*a(n-1) -26*a(n-2) -49*a(n-3) +313*a(n-4) -148*a(n-5) -1278*a(n-6) +1613*a(n-7) +2503*a(n-8) -5004*a(n-9) -2294*a(n-10) +8211*a(n-11) +238*a(n-12) -8046*a(n-13) +1466*a(n-14) +4882*a(n-15) -1384*a(n-16) -1838*a(n-17) +564*a(n-18) +420*a(n-19) -109*a(n-20) -54*a(n-21) +8*a(n-22) +3*a(n-23)

Example

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

Crossrefs

Sequence in context: A202373 A232119 A232417 * A356643 A022049 A107513

Adjacent sequences: A250994 A250995 A250996 * A250998 A250999 A251000

Keyword

nonn

Author

R. H. Hardin, Nov 29 2014

Status

approved