A246742 Number of length 5+4 0..n arrays with no pair in any consecutive five terms totalling exactly n

2, 40, 2436, 19992, 231414, 1152576, 6272072, 22219408, 79002090, 220032120, 600454092, 1407554280, 3218159966, 6646694992, 13405336464, 25160170656, 46234874322, 80560371528, 137811490580, 226332464440, 365838595782

Offset

1,1

Comments

Row 5 of A246737

Links

R. H. Hardin, Table of n, a(n) for n = 1..66

Formula

Empirical: a(n) = 3*a(n-1) +4*a(n-2) -20*a(n-3) +56*a(n-5) -28*a(n-6) -84*a(n-7) +70*a(n-8) +70*a(n-9) -84*a(n-10) -28*a(n-11) +56*a(n-12) -20*a(n-14) +4*a(n-15) +3*a(n-16) -a(n-17)

Example

Some solutions for n=4
..2....4....1....0....0....0....1....2....4....0....0....1....4....0....1....3
..4....3....1....0....1....1....2....0....1....1....0....1....1....3....4....2
..4....3....0....0....0....1....4....1....4....1....2....4....4....2....1....3
..1....3....2....3....2....1....1....1....1....0....0....4....4....3....4....3
..4....4....1....3....1....1....1....0....4....0....0....4....4....3....1....4
..1....3....1....3....1....0....1....2....4....1....0....2....2....3....1....3
..1....4....0....2....1....0....4....0....1....2....1....4....3....3....1....3
..4....4....1....3....4....1....2....1....2....0....2....1....3....0....4....3
..4....4....0....0....1....0....4....0....4....1....0....1....3....2....1....4

Crossrefs

Sequence in context: A060079 A052502 A209289 * A293950 A104134 A358160

Adjacent sequences: A246739 A246740 A246741 * A246743 A246744 A246745

Keyword

nonn

Author

R. H. Hardin, Sep 02 2014

Status

approved