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A269469 Number of length-5 0..n arrays with no repeated value equal to the previous repeated value. 1
14, 174, 852, 2780, 7170, 15834, 31304, 56952, 97110, 157190, 243804, 364884, 529802, 749490, 1036560, 1405424, 1872414, 2455902, 3176420, 4056780, 5122194, 6400394, 7921752, 9719400, 11829350, 14290614, 17145324, 20438852, 24219930 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
FORMULA
Empirical: a(n) = n^5 + 5*n^4 + 7*n^3 + 2*n^2 - n.
Conjectures from Colin Barker, Jan 23 2019: (Start)
G.f.: 2*x*(7 + 45*x + 9*x^2 - x^3) / (1 - x)^6.
a(n) = 6*a(n-1) - 15*a(n-2) + 20*a(n-3) - 15*a(n-4) + 6*a(n-5) - a(n-6) for n>6.
(End)
EXAMPLE
Some solutions for n=3:
..0. .1. .1. .3. .3. .2. .0. .3. .2. .2. .0. .3. .3. .2. .1. .1
..3. .1. .3. .2. .3. .2. .3. .1. .0. .1. .1. .3. .2. .3. .2. .3
..1. .2. .0. .3. .0. .1. .1. .3. .0. .0. .3. .0. .2. .2. .1. .2
..0. .2. .3. .0. .3. .3. .2. .2. .1. .0. .3. .1. .1. .3. .2. .1
..3. .0. .3. .2. .2. .3. .3. .2. .1. .2. .0. .2. .0. .3. .2. .3
CROSSREFS
Row 5 of A269467.
Sequence in context: A061484 A097583 A269680 * A349858 A144506 A177072
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 27 2016
STATUS
approved

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Last modified February 29 17:04 EST 2024. Contains 370427 sequences. (Running on oeis4.)