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A269498 Number of length-7 0..n arrays with no repeated value differing from the previous repeated value by one. 1
66, 1609, 13946, 71115, 263794, 791381, 2039274, 4686391, 9847970, 19258689, 35501146, 62284739, 104779986, 170013325, 267327434, 408912111, 610410754, 891607481, 1277199930, 1797662779, 2490207026, 3399840069, 4580531626 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Row 7 of A269494.

LINKS

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

FORMULA

Empirical: a(n) = n^7 + 7*n^6 + 21*n^5 + 15*n^4 + 7*n^3 + 17*n^2 - n - 1.

Empirical: x*(66 +1081*x +2922*x^2 +903*x^3 -122*x^4 +207*x^5 -18*x^6 +x^7) / (x-1)^8 . - R. J. Mathar, Mar 03 2016

EXAMPLE

Some solutions for n=4

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

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

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

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

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

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

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

CROSSREFS

Cf. A269494.

Sequence in context: A251047 A279889 A241799 * A133318 A197645 A270847

Adjacent sequences:  A269495 A269496 A269497 * A269499 A269500 A269501

KEYWORD

nonn

AUTHOR

R. H. Hardin, Feb 28 2016

STATUS

approved

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Last modified October 22 06:02 EDT 2018. Contains 316432 sequences. (Running on oeis4.)