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A209587 Number of n X n 0..2 arrays with every element equal to a diagonal or antidiagonal reflection 1
3, 81, 3645, 1476225, 996451875, 6053445140625, 61291132048828125, 5585154407949462890625, 848245325707324676513671875, 1159445329576199417209625244140625 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 2 of A209593

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..30

FORMULA

a(n) = 3 ^ (2*n-(n modulo 2)) * 15 ^ ((n*n-2*n+(n modulo 2))/4)

EXAMPLE

Some solutions for n=3

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

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

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

CROSSREFS

Sequence in context: A116179 A013732 A292974 * A223736 A207229 A223717

Adjacent sequences:  A209584 A209585 A209586 * A209588 A209589 A209590

KEYWORD

nonn

AUTHOR

R. H. Hardin Mar 10 2012

STATUS

approved

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Last modified October 30 02:32 EDT 2020. Contains 338076 sequences. (Running on oeis4.)