A062716 - OEIS

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A062716

Number of arrangements of 1,2,..,n*n in an n X n matrix such that each row is increasing or decreasing.

1, 2, 24, 13440, 1009008000, 19947543780003840, 170891375144777551827763200, 942542805268120269309770939139883008000, 4650425326497486529782791149613966242353671284224000000

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,2

LINKS

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

FORMULA

a(1) = 1 and for n >= 2: a(n) = 2^n * A034841(n) = 2^n * (n^2)! / (n!)^n.

CROSSREFS

Cf. A034841.

Sequence in context: A088600 A066120 A152687 * A344664 A137888 A229333

Adjacent sequences: A062713 A062714 A062715 * A062717 A062718 A062719

KEYWORD

nonn

AUTHOR

Ahmed Fares (ahmedfares(AT)my-deja.com), Jul 14 2001

EXTENSIONS

More terms from Vladeta Jovovic, Jul 18 2001

STATUS

approved