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A269540
Number of length-6 0..n arrays with no repeated value differing from the previous repeated value by other than one.
1
22, 418, 2878, 12214, 38878, 102202, 234358, 485038, 926854, 1661458, 2826382, 4602598, 7222798, 10980394, 16239238, 23444062, 33131638, 45942658, 62634334, 84093718, 111351742, 145597978, 188196118, 240700174, 304871398, 382695922
OFFSET
1,1
LINKS
FORMULA
Empirical: a(n) = n^6 + 6*n^5 + 5*n^4 + 12*n^3 - 6*n^2 + 6*n - 2.
Conjectures from Colin Barker, Jan 24 2019: (Start)
G.f.: 2*x*(11 + 132*x + 207*x^2 + 38*x^3 - 21*x^4 - 6*x^5 - x^6) / (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>7.
(End)
EXAMPLE
Some solutions for n=3:
..0. .3. .3. .2. .3. .1. .1. .3. .1. .3. .0. .0. .1. .1. .0. .1
..2. .2. .2. .3. .3. .2. .3. .2. .2. .3. .1. .0. .1. .2. .1. .3
..2. .0. .0. .3. .0. .0. .1. .2. .0. .0. .3. .2. .2. .1. .2. .1
..3. .3. .2. .2. .3. .2. .1. .1. .0. .1. .2. .1. .3. .0. .2. .3
..1. .1. .1. .0. .2. .2. .3. .3. .1. .2. .3. .2. .0. .2. .0. .0
..3. .2. .2. .2. .0. .1. .2. .3. .2. .2. .2. .1. .2. .2. .1. .1
CROSSREFS
Row 6 of A269537.
Sequence in context: A049663 A246645 A183539 * A095219 A299320 A014904
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 29 2016
STATUS
approved