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A187861 Number of 6-step one space for components leftwards or up, two space for components rightwards or down asymmetric quasi-queen's tours (antidiagonal moves become knight moves) on an n X n board summed over all starting positions. 1
0, 0, 846, 9932, 47962, 126397, 262409, 452766, 707541, 1017934, 1387600, 1813854, 2296696, 2836126, 3432144, 4084750, 4793944, 5559726, 6382096, 7261054, 8196600, 9188734, 10237456, 11342766, 12504664, 13723150, 14998224, 16329886, 17718136 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

Row 6 of A187857.

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..50

FORMULA

Empirical: a(n) = 28294*n^2 - 224508*n + 433614 for n>9.

Conjectures from Colin Barker, Apr 26 2018: (Start)

G.f.: x^3*(846 + 7394*x + 20704*x^2 + 11461*x^3 + 17172*x^4 - 3232*x^5 + 10073*x^6 - 8800*x^7 + 3655*x^8 - 2685*x^9) / (1 - x)^3.

a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3) for n>12.

(End)

EXAMPLE

Some solutions for 4 X 4:

..0..0..0..0....5..0..6..0....0..3..2..6....0..0..1..0....0..0..0..1

..3..2..4..0....4..3..0..0....1..0..0..5....0..5..0..0....0..0..3..0

..0..1..0..0....0..0..2..0....0..0..0..4....3..2..4..0....6..5..2..0

..6..5..0..0....1..0..0..0....0..0..0..0....6..0..0..0....0..0..4..0

CROSSREFS

Cf. A187857.

Sequence in context: A323253 A160212 A188296 * A280484 A203335 A252253

Adjacent sequences:  A187858 A187859 A187860 * A187862 A187863 A187864

KEYWORD

nonn

AUTHOR

R. H. Hardin, Mar 14 2011

STATUS

approved

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Last modified December 5 00:18 EST 2021. Contains 349529 sequences. (Running on oeis4.)