login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A187515 Number of 10-step S, E, and NW-moving king's tours on an n X n board summed over all starting positions. 1
0, 0, 0, 398, 3868, 13796, 31548, 56952, 89684, 129637, 176796, 231161, 292732, 361509, 437492, 520681, 611076, 708677, 813484, 925497, 1044716, 1171141, 1304772, 1445609, 1593652, 1748901, 1911356, 2081017, 2257884, 2441957, 2633236 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,4

COMMENTS

Row 10 of A187507.

LINKS

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

FORMULA

Empirical: a(n) = 3603*n^2 - 28504*n + 54377 for n>8.

Conjectures from Colin Barker, Apr 24 2018: (Start)

G.f.: x^4*(398 + 2674*x + 3386*x^2 + 1366*x^3 - 172*x^4 - 324*x^5 - 107*x^6 - 15*x^7) / (1 - x)^3.

a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3) for n>11.

(End)

EXAMPLE

Some solutions for 4 X 4:

..1..0..0..0....7..8..9.10....0..7..8..9....0..5..0..1....0..0..0..1

..2..3..4..5....0..6..0..0....4..5..6.10....8..6..4..2....0..0..0..2

..0.10..8..6....0..4..5..0....0..3..1..0....9..7..0..3....9..7..5..3

..0..0..9..7....1..2..3..0....0..0..2..0...10..0..0..0...10..8..6..4

CROSSREFS

Cf. A187507.

Sequence in context: A158316 A236713 A235958 * A235569 A261768 A274446

Adjacent sequences:  A187512 A187513 A187514 * A187516 A187517 A187518

KEYWORD

nonn

AUTHOR

R. H. Hardin, Mar 10 2011

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified October 16 20:36 EDT 2021. Contains 348047 sequences. (Running on oeis4.)