[go: up one dir, main page]

login
A247406
Number of length 2+4 0..n arrays with no disjoint pairs in any consecutive five terms having the same sum
1
0, 40, 264, 1544, 6216, 19080, 49032, 113896, 237456, 466640, 856512, 1494696, 2491584, 4009888, 6231576, 9423824, 13882728, 20009088, 28250184, 39194656, 53468496, 71900744, 95363904, 124954128, 161852112, 207511288, 263443896
OFFSET
1,2
COMMENTS
Row 2 of A247404
LINKS
FORMULA
Empirical: a(n) = a(n-1) +a(n-3) +a(n-4) -a(n-5) -2*a(n-7) -a(n-8) -a(n-9) +a(n-11) +3*a(n-12) +a(n-13) +2*a(n-14) -2*a(n-16) -a(n-17) -3*a(n-18) -a(n-19) +a(n-21) +a(n-22) +2*a(n-23) +a(n-25) -a(n-26) -a(n-27) -a(n-29) +a(n-30)
EXAMPLE
Some solutions for n=6
..5....5....0....6....1....2....5....4....4....3....0....0....6....0....5....0
..4....3....6....5....6....6....6....5....3....5....5....6....6....1....4....6
..2....0....2....2....3....6....5....4....3....5....5....3....3....5....0....4
..2....3....6....0....3....0....2....6....0....5....5....2....6....2....4....1
..6....3....6....0....2....3....0....1....5....0....3....2....1....0....4....4
..2....2....5....1....3....6....0....6....3....2....6....4....6....5....5....0
CROSSREFS
Sequence in context: A290127 A115170 A374240 * A229588 A334121 A117216
KEYWORD
nonn
AUTHOR
R. H. Hardin, Sep 16 2014
STATUS
approved