A233840 Number of (n+2) X (3+2) 0..3 arrays with no increasing sequence of length 3 horizontally or antidiagonally downwards.

480071296, 326595297792, 220722832237568, 149185819914631168, 100827647839987847168, 68144762665642379485184, 46055875906826738439045120, 31127025414950384068108124160

Offset

1,1

Comments

Column 3 of A233845.

Links

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

Formula

Empirical: a(n) = 676*a(n-1) +6980*a(n-2) -4863328*a(n-3) +41995792*a(n-4) +7953854528*a(n-5) -184904579136*a(n-6) +809889143808*a(n-7) +10973630976000*a(n-8) -119806280073216*a(n-9) +355504517218304*a(n-10) +141549729742848*a(n-11) -1945470193631232*a(n-12) +423049732030464*a(n-13) +1344200025047040*a(n-14) -382139212234752*a(n-15) +171684875206656*a(n-16).

Example

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

Crossrefs

Cf. A233845.

Sequence in context: A011523 A172535 A181728 * A203671 A251307 A287550

Adjacent sequences: A233837 A233838 A233839 * A233841 A233842 A233843

Keyword

nonn

Author

R. H. Hardin, Dec 16 2013

Status

approved