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A263592 Number of length n arrays of permutations of 0..n-1 with each element moved by -3 to 3 places and the median of every three consecutive elements nondecreasing. 1
1, 2, 6, 16, 41, 108, 280, 729, 1908, 4969, 12950, 33796, 88112, 229740, 599191, 1562470, 4074372, 10625188, 27707446, 72253034, 188417568, 491341657, 1281284446, 3341248089, 8713071846, 22721332009, 59251115518, 154510913809 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

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

FORMULA

Empirical: a(n) = a(n-1) + a(n-2) + 7*a(n-3) + 2*a(n-4) + 4*a(n-5) - a(n-7) - a(n-8).

Empirical g.f.: x*(1 + x + 3*x^2 + x^3 + 3*x^4 + x^5 - x^6 - x^7) / (1 - x - x^2 - 7*x^3 - 2*x^4 - 4*x^5 + x^7 + x^8). - Colin Barker, Jan 02 2019

EXAMPLE

Some solutions for n=6:

..2....1....0....1....3....0....1....1....1....0....0....2....0....1....0....0

..0....0....1....0....1....1....0....0....0....1....3....0....4....0....1....1

..3....2....5....4....0....3....3....5....2....2....2....4....1....3....2....2

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

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

..4....5....4....5....2....2....2....4....3....3....5....5....5....4....5....3

CROSSREFS

Column 3 of A263597.

Sequence in context: A068786 A276359 A158920 * A178438 A143123 A102699

Adjacent sequences: A263589 A263590 A263591 * A263593 A263594 A263595

KEYWORD

nonn

AUTHOR

R. H. Hardin, Oct 22 2015

STATUS

approved

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Last modified February 6 11:45 EST 2023. Contains 360104 sequences. (Running on oeis4.)