A247399 Number of length n+4 0..3 arrays with no disjoint pairs in any consecutive five terms having the same sum.

200, 264, 340, 428, 528, 640, 864, 1136, 1456, 1824, 2240, 3072, 4096, 5312, 6720, 8320, 11520, 15488, 20224, 25728, 32000, 44544, 60160, 78848, 100608, 125440, 175104, 237056, 311296, 397824, 496640, 694272, 941056, 1236992, 1582080

Offset

1,1

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = 6*a(n-5) - 8*a(n-10).

Empirical g.f.: 4*x*(50 + 66*x + 85*x^2 + 107*x^3 + 132*x^4 - 140*x^5 - 180*x^6 - 226*x^7 - 278*x^8 - 336*x^9) / ((1 - 2*x^5)*(1 - 4*x^5)). - Colin Barker, Nov 07 2018

Example

Some solutions for n=6:
..3....2....1....0....0....0....3....3....1....3....1....3....2....1....2....1
..2....3....0....0....0....2....3....2....1....0....1....3....1....2....1....3
..2....3....3....0....2....0....2....1....1....1....3....3....3....0....0....3
..0....0....3....2....0....1....0....1....2....0....1....1....1....2....2....2
..2....3....3....3....3....0....3....1....3....0....0....2....1....2....2....3
..1....1....2....0....0....0....3....3....1....3....1....3....0....1....2....1
..2....3....0....0....0....2....3....2....1....0....1....3....1....2....1....3
..2....3....3....0....2....0....2....1....1....1....3....3....3....0....0....3
..0....0....3....2....0....3....0....1....0....0....1....1....1....2....2....2
..2....3....3....1....3....0....3....1....3....0....0....2....1....2....2....3

Crossrefs

Column 3 of A247404.

Sequence in context: A192545 A118118 A124472 * A078492 A166256 A252059

Adjacent sequences: A247396 A247397 A247398 * A247400 A247401 A247402

Keyword

nonn

Author

R. H. Hardin, Sep 16 2014

Status

approved