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A269531
Number of length-n 0..2 arrays with no repeated value differing from the previous repeated value by other than one.
1
3, 9, 24, 64, 164, 418, 1048, 2614, 6468, 15942, 39120, 95734, 233660, 569230, 1384408, 3362686, 8158932, 19778982, 47913504, 115999462, 280698860, 678970558, 1641785704, 3968834446, 9592037508, 23178077334, 55998523824, 135275792374
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OFFSET
1,1
LINKS
R. H. Hardin,
Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 4*a(n-1) - a(n-2) - 10*a(n-3) + 6*a(n-4) + 4*a(n-5).
Empirical g.f.: x*(3 - 3*x - 9*x^2 + 7*x^3 + 4*x^4) / ((1 - 2*x)*(1 - 2*x - x^2)*(1 - 2*x^2)). -
Colin Barker
, Jan 23 2019
EXAMPLE
Some solutions for n=9:
..1. .0. .0. .0. .1. .0. .2. .0. .1. .0. .0. .2. .0. .0. .0. .1
..0. .1. .2. .2. .1. .2. .1. .2. .0. .1. .0. .0. .1. .2. .2. .1
..1. .2. .0. .0. .0. .0. .2. .0. .1. .0. .2. .0. .2. .0. .0. .2
..1. .0. .2. .2. .2. .2. .0. .1. .0. .1. .1. .1. .1. .0. .1. .1
..0. .0. .2. .1. .1. .2. .0. .0. .0. .0. .1. .2. .0. .2. .1. .0
..0. .1. .0. .2. .2. .1. .2. .1. .2. .2. .0. .1. .1. .0. .0. .2
..2. .1. .2. .1. .0. .2. .1. .0. .1. .0. .2. .0. .2. .2. .1. .1
..1. .0. .1. .0. .2. .1. .1. .1. .0. .1. .2. .2. .0. .0. .0. .0
..0. .1. .0. .1. .1. .2. .0. .0. .1. .2. .0. .1. .1. .1. .1. .1
CROSSREFS
Column 2 of
A269537
.
Sequence in context:
A166290
A097134
A123892
*
A064831
A153582
A269461
Adjacent sequences:
A269528
A269529
A269530
*
A269532
A269533
A269534
KEYWORD
nonn
AUTHOR
R. H. Hardin
, Feb 29 2016
STATUS
approved
