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A187510
Number of 5-step S, E, and NW-moving king's tours on an n X n board summed over all starting positions
1
0, 0, 40, 184, 435, 788, 1243, 1800, 2459, 3220, 4083, 5048, 6115, 7284, 8555, 9928, 11403, 12980, 14659, 16440, 18323, 20308, 22395, 24584, 26875, 29268, 31763, 34360, 37059, 39860, 42763, 45768, 48875, 52084, 55395, 58808, 62323, 65940, 69659, 73480
OFFSET
1,3
COMMENTS
Row 5 of A187507
LINKS
FORMULA
Empirical: a(n) = 51*n^2 - 208*n + 200 for n>3.
Empirical G.f.: x^3*(40+64*x+3*x^2-5*x^3)/(1-x)^3. [Colin Barker, Jan 22 2012]
EXAMPLE
Some solutions for 4X4
..0..0..0..0....0..0..0..0....0..0..0..0....4..0..0..0....0..1..0..0
..0..0..0..0....0..0..0..0....4..5..0..0....5..3..1..0....0..2..0..0
..0..5..3..1....0..0..4..5....2..3..0..0....0..0..2..0....0..3..4..5
..0..0..4..2....0..1..2..3....0..1..0..0....0..0..0..0....0..0..0..0
CROSSREFS
Sequence in context: A251210 A211497 A251203 * A187379 A077818 A247405
KEYWORD
nonn
AUTHOR
R. H. Hardin Mar 10 2011
STATUS
approved