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A263711 Number of length n arrays of permutations of 0..n-1 with each element moved by -2 to 2 places and every four consecutive elements having its maximum within 4 of its minimum. 1
1, 2, 6, 14, 31, 34, 39, 46, 64, 104, 161, 249, 385, 561, 845, 1254, 1871, 2833, 4228, 6359, 9545, 14273, 21453, 32133, 48184, 72323, 108363, 162592, 243817, 365545, 548369, 822181, 1233053, 1849282, 2772959, 4158841, 6236608, 9352579, 14026153 (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-3) - a(n-4) + 2*a(n-5) - a(n-6) + a(n-7) for n>18.

Empirical g.f.: x*(1 + x + 4*x^2 + 7*x^3 + 16*x^4 - 3*x^5 - 6*x^6 - 21*x^7 - 9*x^8 - 19*x^9 - x^10 - 5*x^11 + 9*x^12 - 2*x^13 + 6*x^14 - 9*x^15 - 4*x^17) / (1 - x - x^3 + x^4 - 2*x^5 + x^6 - x^7). - Colin Barker, Jan 02 2019

EXAMPLE

Some solutions for n=7:

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

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

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

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

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

..6....4....5....6....6....6....5....5....5....5....3....5....5....6....5....3

..5....6....6....5....5....5....6....6....6....6....6....6....6....5....6....6

CROSSREFS

Column 2 of A263714.

Sequence in context: A059076 A237623 A232059 * A263697 A291409 A263746

Adjacent sequences:  A263708 A263709 A263710 * A263712 A263713 A263714

KEYWORD

nonn

AUTHOR

R. H. Hardin, Oct 24 2015

STATUS

approved

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Last modified May 19 16:36 EDT 2019. Contains 323395 sequences. (Running on oeis4.)