OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 3*a(n-1) - 8*a(n-3) + 6*a(n-4) + 6*a(n-5) - 8*a(n-6) + 3*a(n-8) - a(n-9).
Conjectures from Colin Barker, Nov 04 2018: (Start)
G.f.: x*(68 + 1077*x + 781*x^2 + 633*x^3 - 1143*x^4 - 561*x^5 + 103*x^6 + 3*x^7 - x^8) / ((1 - x)^6*(1 + x)^3).
a(n) = 1 + 22*n + 31*n^2 + 77*n^3 + 29*n^4 + n^5 for n even.
a(n) = -5 - 44*n + 10*n^2 + 77*n^3 + 29*n^4 + n^5 for n odd.
(End)
EXAMPLE
Some solutions for n=8:
..2....4....4....0....0....4....3....3....1....0....1....2....0....3....0....3
..6....4....1....8....8....4....6....6....7....8....8....2....7....7....8....7
..2....4....7....0....7....7....2....5....1....1....0....6....1....1....8....1
..2....8....4....6....1....1....3....3....4....7....2....2....3....1....0....0
..6....0....4....2....6....7....5....8....4....6....6....3....5....7....6....8
..5....3....4....6....2....1....5....0....5....1....3....5....3....3....2....8
..2....5....7....3....1....3....3....8....4....7....5....5....5....5....5....0
..6....4....1....2....6....5....4....0....3....4....7....3....3....5....3....5
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Aug 04 2014
STATUS
approved