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A211885 Number of lower triangular n X n arrays of integers 0 upwards introduced in row major order, with each element unique in its row and column, and containing the value n(n+1)/2-2 0
0, 2, 8, 26, 66, 141, 267, 463, 751 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Column 1 of A211888

LINKS

Table of n, a(n) for n=1..9.

EXAMPLE

Some solutions for n=4

..0........0........0........0........0........0........0........0

..1.2......1.2......1.2......1.2......1.0......1.2......1.2......1.2

..3.4.1....3.4.5....3.4.5....3.4.5....2.3.4....3.4.5....3.4.5....3.4.5

..5.6.7.8..6.7.8.9..6.7.3.8..2.6.7.8..5.6.7.8..6.7.8.3..6.3.7.8..6.7.8.1

CROSSREFS

Sequence in context: A100504 A327600 A099416 * A101696 A155861 A212140

Adjacent sequences:  A211882 A211883 A211884 * A211886 A211887 A211888

KEYWORD

nonn

AUTHOR

R. H. Hardin Apr 24 2012

STATUS

approved

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Last modified September 17 19:58 EDT 2021. Contains 347489 sequences. (Running on oeis4.)