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A269692 Number of length-6 0..n arrays with no repeated value differing from the previous repeated value by plus or minus one modulo n+1. 1
40, 525, 3544, 14465, 44556, 114205, 256880, 523809, 989380, 1757261, 2967240, 4802785, 7499324, 11353245, 16731616, 24082625, 33946740, 46968589, 63909560, 85661121, 113258860, 147897245, 190945104, 243961825, 308714276, 387194445 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
FORMULA
Empirical: a(n) = n^6 + 6*n^5 + 15*n^4 + 8*n^3 - 7*n^2 - 4*n + 1 for n>1.
Conjectures from Colin Barker, Jan 28 2019: (Start)
G.f.: x*(40 + 245*x + 709*x^2 - 718*x^3 + 750*x^4 - 427*x^5 + 141*x^6 - 20*x^7) / (1 - x)^7.
a(n) = 7*a(n-1) - 21*a(n-2) + 35*a(n-3) - 35*a(n-4) + 21*a(n-5) - 7*a(n-6) + a(n-7) for n>8.
(End)
EXAMPLE
Some solutions for n=3:
..3. .3. .1. .0. .2. .1. .2. .1. .1. .1. .2. .1. .3. .3. .2. .1
..2. .2. .0. .1. .0. .3. .1. .2. .1. .2. .3. .1. .3. .0. .0. .1
..2. .2. .1. .3. .1. .0. .1. .1. .1. .1. .2. .0. .1. .1. .3. .0
..0. .0. .0. .3. .3. .1. .1. .0. .2. .2. .1. .3. .1. .3. .1. .2
..3. .2. .3. .1. .1. .1. .0. .0. .3. .0. .2. .1. .0. .3. .1. .1
..1. .2. .1. .2. .1. .2. .3. .0. .3. .0. .2. .2. .3. .3. .2. .0
CROSSREFS
Row 6 of A269690.
Sequence in context: A069079 A093744 A109105 * A247409 A107419 A159946
KEYWORD
nonn
AUTHOR
R. H. Hardin, Mar 03 2016
STATUS
approved

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Last modified March 3 14:56 EST 2024. Contains 370512 sequences. (Running on oeis4.)