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A233491
Number of (n+2)X(2+2) 0..2 arrays with no increasing sequence of length 3 horizontally or antidiagonally downwards
1
388908, 26851581, 1853443458, 127934319483, 8830686982464, 609539583118581, 42073567268258250, 2904134713566546240, 200458363340939984253, 13836670608153772979775, 955078402954534730110719
OFFSET
1,1
COMMENTS
Column 2 of A233497
LINKS
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
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 11 2013
STATUS
approved