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A269439 Number of length-7 0..n arrays with no repeated value greater than the previous repeated value. 1
92, 1722, 13868, 69235, 255576, 767172, 1981512, 4566213, 9621220, 18861326, 34844052, 61247927, 103206208, 167701080, 264023376, 404302857, 604114092, 883162978, 1266058940, 1783177851, 2471620712, 3376273132, 4550970648 (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 + 7*n^6 + 16*n^5 + (71/3)*n^4 + (139/6)*n^3 + (43/3)*n^2 + (35/6)*n + 1.

Conjectures from Colin Barker, Jan 22 2019: (Start)

G.f.: x*(92 + 986*x + 2668*x^2 + 1355*x^3 + 8*x^4 - 76*x^5 + 8*x^6 - x^7) / (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=4:

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

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

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

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

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

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

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

CROSSREFS

Row 7 of A269435.

Sequence in context: A265968 A179798 A232795 * A269623 A265923 A249236

Adjacent sequences:  A269436 A269437 A269438 * A269440 A269441 A269442

KEYWORD

nonn

AUTHOR

R. H. Hardin, Feb 26 2016

STATUS

approved

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Last modified May 18 23:41 EDT 2021. Contains 344009 sequences. (Running on oeis4.)