A234394 Number of (1+2)X(n+2) 0..3 arrays with no increasing sequence of length 3 horizontally or diagonally downwards

196316, 10683130, 585790562, 32129615500, 1761338821822, 96553476935058, 5293088906692756, 290169408255194858, 15907169753200518438, 872035377995319811964, 47805225784776928099734, 2620696036046778403201050

Offset

1,1

Comments

Row 1 of A234393

Links

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

Formula

Empirical: a(n) = 59*a(n-1) -321*a(n-2) +5250*a(n-3) +11912*a(n-4) -1362734*a(n-5) +2774640*a(n-6) +51543392*a(n-7) -111860552*a(n-8) -142606384*a(n-9) -375586128*a(n-10) -4285167120*a(n-11) +4322222432*a(n-12) -4985269824*a(n-13) +9926880896*a(n-14) +25978108928*a(n-15) -24346223616*a(n-16) +12931098624*a(n-17) -20510392320*a(n-18) -28179726336*a(n-19) +22454599680*a(n-20)

Example

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

Crossrefs

Sequence in context: A234996 A234389 A234393 * A202434 A179253 A008408

Adjacent sequences: A234391 A234392 A234393 * A234395 A234396 A234397

Keyword

nonn

Author

R. H. Hardin, Dec 25 2013

Status

approved