login
A247528
Number of length n+3 0..3 arrays with some disjoint pairs in every consecutive four terms having the same sum.
1
88, 136, 220, 364, 604, 1018, 1732, 2956, 5050, 8638, 14794, 25348, 43438, 74446, 127606, 218740, 374968, 642784, 1101898, 1888954, 3238192, 5551168, 9516268, 16313584, 27966124, 47941900, 82186078, 140890372, 241526284, 414044950
OFFSET
1,1
LINKS
FORMULA
Empirical: a(n) = 2*a(n-1) - a(n-3) + a(n-4) - a(n-5) - a(n-6) + a(n-7).
Empirical g.f.: 2*x*(44 - 20*x - 26*x^2 + 6*x^3 - 38*x^4 - 9*x^5 + 32*x^6) / ((1 - x)*(1 - x - x^2 - x^4 + x^6)). - Colin Barker, Nov 07 2018
EXAMPLE
Some solutions for n=6:
..2....0....2....0....0....2....3....3....2....2....0....1....3....3....0....2
..3....1....0....1....1....3....2....2....1....1....1....1....0....3....1....1
..1....3....1....1....3....1....2....1....2....1....0....0....0....2....1....0
..0....2....3....2....2....2....1....2....3....2....1....2....3....2....2....3
..2....2....2....2....0....0....1....1....2....2....2....1....3....1....0....2
..1....1....0....1....1....1....2....2....1....1....1....3....0....3....1....1
..1....1....1....3....1....1....0....1....2....3....2....0....0....2....1....2
..0....0....1....0....0....2....1....0....3....0....1....2....3....2....2....3
..2....2....2....2....0....2....3....1....2....2....2....1....3....3....0....0
CROSSREFS
Column 3 of A247533.
Sequence in context: A225136 A039445 A300144 * A346774 A249555 A226587
KEYWORD
nonn
AUTHOR
R. H. Hardin, Sep 18 2014
STATUS
approved