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A267236 Number of length-7 0..n arrays with no following elements greater than or equal to the first repeated value. 1
9, 479, 5646, 34396, 143695, 469623, 1291052, 3121008, 6830757, 13811655, 26179802, 47028540, 80733835, 133317583, 212873880, 330063296, 498680193, 736298127, 1064998374, 1512186620, 2111502855, 2903829511, 3938402884 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

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

FORMULA

Empirical: a(n) = n^7 + (69/20)*n^6 + (7/2)*n^5 + (7/6)*n^4 - (7/60)*n^2.

Conjectures from Colin Barker, Jan 10 2019: (Start)

G.f.: x*(9 + 407*x + 2066*x^2 + 2136*x^3 + 421*x^4 + x^5) / (1 - x)^8.

a(n) = 8*a(n-1) - 28*a(n-2) + 56*a(n-3) - 70*a(n-4) + 56*a(n-5) - 28*a(n-6) + 8*a(n-7) - a(n-8) for n>8.

(End)

EXAMPLE

Some solutions for n=5:

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

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

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

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

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

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

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

CROSSREFS

Row 7 of A267232.

Sequence in context: A213447 A128947 A293951 * A306820 A157595 A042415

Adjacent sequences:  A267233 A267234 A267235 * A267237 A267238 A267239

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jan 12 2016

STATUS

approved

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Last modified September 27 01:55 EDT 2020. Contains 337379 sequences. (Running on oeis4.)