A251795 Number of (n+1)X(2+1) 0..3 arrays with no 2X2 subblock having x11-x00 less than x10-x01

1080, 28932, 724300, 18577404, 474547100, 12140516092, 310512400748, 7942655953980, 203162998830364, 5196687753697688, 132925430781676964, 3400084831220237312, 86970384462156604888, 2224605686320053022252

Offset

1,1

Comments

Column 2 of A251801

Links

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

Formula

Empirical: a(n) = 30*a(n-1) -40*a(n-2) -2202*a(n-3) +7167*a(n-4) +41092*a(n-5) -170647*a(n-6) -169762*a(n-7) +1201353*a(n-8) -237196*a(n-9) -3305290*a(n-10) +2262184*a(n-11) +3737187*a(n-12) -3793360*a(n-13) -1475516*a(n-14) +2385944*a(n-15) -12352*a(n-16) -613952*a(n-17) +105792*a(n-18) +54144*a(n-19) -13824*a(n-20)

Example

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

Crossrefs

Sequence in context: A159210 A250538 A281259 * A092135 A077740 A338407

Adjacent sequences: A251792 A251793 A251794 * A251796 A251797 A251798

Keyword

nonn

Author

R. H. Hardin, Dec 09 2014

Status

approved