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A221621 Number of nX6 arrays with each row a permutation of 1..6 having at least as many downsteps as the preceding row 1
720, 353654, 148700748, 57614883627, 21241004664348, 7575106427737240, 2638115823321645192, 902542985526634773509, 304529313276100670030616, 101620178879261858322711162, 33604296810830843896378600020 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 6 of A221623

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..210

FORMULA

Empirical: a(n) = 720*a(n-1) -164746*a(n-2) +12686988*a(n-3) -321204409*a(n-4) +605003244*a(n-5) -296321796*a(n-6)

EXAMPLE

Some solutions for n=3

..4..1..2..5..3..6....4..1..2..5..3..6....4..1..2..5..3..6....4..1..2..5..3..6

..1..4..6..3..5..2....3..1..2..5..4..6....4..1..2..6..5..3....3..1..5..4..6..2

..2..1..4..3..6..5....3..6..2..5..4..1....5..4..6..3..1..2....2..1..4..3..6..5

CROSSREFS

Sequence in context: A003439 A222158 A145093 * A054779 A030185 A227668

Adjacent sequences:  A221618 A221619 A221620 * A221622 A221623 A221624

KEYWORD

nonn

AUTHOR

R. H. Hardin Jan 21 2013

STATUS

approved

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Last modified May 27 03:13 EDT 2022. Contains 354093 sequences. (Running on oeis4.)