A233491 Number of (n+2)X(2+2) 0..2 arrays with no increasing sequence of length 3 horizontally or antidiagonally downwards

388908, 26851581, 1853443458, 127934319483, 8830686982464, 609539583118581, 42073567268258250, 2904134713566546240, 200458363340939984253, 13836670608153772979775, 955078402954534730110719

Offset

1,1

Comments

Column 2 of A233497

Links

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

Formula

Empirical: a(n) = 69*a(n-1) +18*a(n-2) -1125*a(n-3) +108*a(n-4) +4131*a(n-5) -3402*a(n-6) +729*a(n-7)

Example

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

Crossrefs

Sequence in context: A234216 A258686 A157739 * A319505 A106778 A164987

Adjacent sequences: A233488 A233489 A233490 * A233492 A233493 A233494

Keyword

nonn

Author

R. H. Hardin, Dec 11 2013

Status

approved