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A267230 Number of length-n 0..6 arrays with no following elements greater than or equal to the first repeated value. 1
7, 49, 315, 1981, 12327, 76237, 469623, 2884909, 17686215, 108259885, 661872471, 4042575277, 24671450343, 150466937773, 917151735159, 5587651325485, 34027698639111, 207144227712301, 1260572274312087, 7668877406965933 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 6 of A267232.

LINKS

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

FORMULA

Empirical: a(n) = 27*a(n-1) - 301*a(n-2) + 1785*a(n-3) - 6034*a(n-4) + 11508*a(n-5) - 11304*a(n-6) + 4320*a(n-7) for n > 8.

Conjectures from Colin Barker, Feb 05 2018: (Start)

G.f.: x*(7 - 140*x + 1099*x^2 - 4270*x^3 + 8428*x^4 - 7476*x^5 + 1512*x^6 + 720*x^7) / ((1 - x)*(1 - 2*x)*(1 - 3*x)*(1 - 4*x)*(1 - 5*x)*(1 - 6*x)^2).

a(n) = (-45*2^n - 40*3^n - 45*4^n - 72*5^n + 557*6^n + 5*2^(1 + n)*3^n*n - 72) / 360 for n>1.

(End)

EXAMPLE

Some solutions for n=6:

  3  2  1  3  1  2  2  0  4  0  2  0  1  3  6  3

  6  6  0  6  2  3  3  3  5  2  4  1  5  4  5  6

  2  1  3  1  0  5  5  2  2  6  3  0  3  1  5  4

  5  3  6  3  4  6  2  5  4  4  1  4  0  4  2  2

  2  1  1  4  1  5  0  1  5  0  6  6  3  2  4  0

  3  0  6  0  1  2  4  1  2  0  6  6  1  4  0  6

CROSSREFS

Cf. A267232.

Sequence in context: A294293 A133046 A200783 * A188868 A267469 A126639

Adjacent sequences:  A267227 A267228 A267229 * A267231 A267232 A267233

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jan 12 2016

STATUS

approved

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Last modified May 12 13:46 EDT 2021. Contains 343823 sequences. (Running on oeis4.)