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A223570 Number of n X n 0..2 arrays with antidiagonals unimodal 1
3, 81, 16038, 16230456, 64207683936, 817235401137408, 28907250609032395776, 2535541672670058530700288, 503424192483622111094950081536, 209983768351036102380925723459562496 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Diagonal of A223576

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..64

FORMULA

Let U(z) = (z^4+6*z^3+23*z^2+18*z+24)/24

a(n) = U(n) * product{ U(i)^2 , i=1..(n-1) }

EXAMPLE

Some solutions for n=3

..1..0..2....0..2..1....2..1..2....1..0..2....0..0..0....1..2..0....0..0..0

..1..1..2....1..1..1....2..2..0....1..0..1....0..1..0....0..1..0....1..0..2

..1..1..0....0..0..0....2..1..1....0..1..2....1..1..1....2..0..0....0..0..0

CROSSREFS

Sequence in context: A207544 A207311 A206693 * A228971 A060722 A183502

Adjacent sequences:  A223567 A223568 A223569 * A223571 A223572 A223573

KEYWORD

nonn

AUTHOR

R. H. Hardin Mar 22 2013

STATUS

approved

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Last modified November 30 05:12 EST 2021. Contains 349419 sequences. (Running on oeis4.)