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A212826
Number of 0..5 arrays of length n with no adjacent pair equal to its immediately preceding adjacent pair, and new values introduced in 0..5 order.
1
1, 2, 5, 13, 44, 168, 716, 3331, 16599, 87059, 473569, 2641428, 14982656, 85930423, 496412949, 2881216925, 16773626497, 97843056510, 571457023718, 3340356838651, 19535838889479, 114293073644447, 668811749036809, 3914263576403496
OFFSET
1,2
COMMENTS
Column 5 of A212829.
LINKS
FORMULA
Empirical: a(n) = 11*a(n-1) - 30*a(n-2) - 21*a(n-3) + 112*a(n-4) + 63*a(n-5) - 119*a(n-6) - 120*a(n-7) - 30*a(n-8) for n>11.
Empirical g.f.: x*(1 + x + x^2)*(1 - 10*x + 22*x^2 + 27*x^3 - 68*x^4 - 67*x^5 + 29*x^6 + 44*x^7 + 11*x^8) / ((1 - x - x^2)*(1 - 2*x - 2*x^2)*(1 - 3*x - 3*x^2)*(1 - 5*x - 5*x^2)). - Colin Barker, Jul 21 2018
EXAMPLE
Some solutions for n=8:
..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0
..0....1....1....1....0....1....1....1....1....1....1....1....1....1....1....1
..1....2....1....2....0....1....1....2....0....1....2....2....0....1....2....1
..0....3....2....0....1....2....2....3....2....2....1....3....2....2....3....0
..2....3....3....0....0....3....3....0....1....1....0....2....2....3....4....2
..3....4....1....0....2....4....2....2....1....0....3....1....2....4....5....3
..1....3....2....1....2....2....4....3....3....0....2....0....3....3....4....2
..1....3....3....1....3....4....3....3....1....2....1....2....1....5....4....0
CROSSREFS
Cf. A212829.
Sequence in context: A375730 A066740 A212825 * A212827 A212828 A212830
KEYWORD
nonn
AUTHOR
R. H. Hardin, May 28 2012
STATUS
approved