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A269490 Number of length-n 0..4 arrays with no repeated value differing from the previous repeated value by one. 1
5, 25, 125, 617, 3021, 14695, 71115, 342749, 1646513, 7888637, 37714065, 179987481, 857744605, 4082846423, 19415519707, 92255164553, 438075822317, 2079098651337, 9863010567565, 46772069428089, 221735120808989, 1050936378053663 (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) = 12*a(n-1) - 43*a(n-2) + 24*a(n-3) + 75*a(n-4) + 20*a(n-5) - a(n-6).

Empirical g.f.: x*(5 - 35*x + 40*x^2 + 72*x^3 + 17*x^4 - x^5) / (1 - 12*x + 43*x^2 - 24*x^3 - 75*x^4 - 20*x^5 + x^6). - Colin Barker, Jan 23 2019

EXAMPLE

Some solutions for n=6:

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

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

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

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

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

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

CROSSREFS

Column 4 of A269494.

Sequence in context: A269579 A269431 A269686 * A269772 A269652 A163844

Adjacent sequences:  A269487 A269488 A269489 * A269491 A269492 A269493

KEYWORD

nonn

AUTHOR

R. H. Hardin, Feb 28 2016

STATUS

approved

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Last modified December 4 02:40 EST 2021. Contains 349469 sequences. (Running on oeis4.)