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A243514
Number of length n+2 0..5 arrays with no three elements in a row with pattern aba or abb (with a!=b) and new values 0..5 introduced in 0..5 order.
1
3, 5, 10, 25, 76, 263, 978, 3773, 14824, 58771, 234046, 934121, 3732372, 14921279, 59668714, 238642069, 954502720, 3817879787, 15271256982, 61084503617, 244336965868, 977345766295, 3909378870850, 15637507094765, 62550011601816
OFFSET
1,1
LINKS
FORMULA
Empirical: a(n) = 8*a(n-1) - 21*a(n-2) + 22*a(n-3) - 8*a(n-4).
Conjectures from Colin Barker, Nov 02 2018: (Start)
G.f.: x*(3 - 19*x + 33*x^2 - 16*x^3) / ((1 - x)^2*(1 - 2*x)*(1 - 4*x)).
a(n) = (26 + 9*2^n + 4^n + 6*n) / 18.
(End)
EXAMPLE
All solutions for n=3:
..0....0....0....0....0....0....0....0....0....0
..1....0....0....0....1....1....1....1....0....0
..2....1....0....1....2....2....2....2....0....0
..0....2....1....2....3....3....3....0....0....0
..1....0....2....3....1....0....4....3....1....0
CROSSREFS
Column 5 of A243519.
Sequence in context: A171867 A243513 A002039 * A243515 A243516 A243517
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jun 05 2014
STATUS
approved