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!)
A195593 Number of ways to place 5n nonattacking kings on a vertical cylinder 10 X 2n. 2
64, 732, 4392, 18890, 66532, 205628, 580664, 1536814, 3877300, 9434784, 22327496, 51698178, 117645348, 263992580, 585640568, 1286898262, 2805399156, 6074441896, 13076687560, 28009586346, 59732295204, 126891641612, 268638308152, 566987715710 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Vertical cylinder: a chessboard where it is supposed that the columns 1 and 10 are in contact (number of columns = 10, number of rows = 2n).

LINKS

Jinyuan Wang, Table of n, a(n) for n = 1..1000

Vaclav Kotesovec, Non-attacking chess pieces

Index entries for linear recurrences with constant coefficients, signature (8,-26,44,-41,20,-4).

FORMULA

a(n) = -4*a(n-6) + 20*a(n-5) - 41*a(n-4) + 44*a(n-3) - 26*a(n-2) + 8*a(n-1).

G.f.: (1 + 56*x + 246*x^2 + 156*x^3 + 11*x^4)/((x-1)^4*(2*x-1)^2).

a(n) = (1771*n - 8709)*2^n + 235/3*n^3 + 880*n^2 + 12815/3*n + 8710.

MATHEMATICA

LinearRecurrence[{8, -26, 44, -41, 20, -4}, {64, 732, 4392, 18890, 66532, 205628}, 20] (* Jinyuan Wang, Feb 26 2020 *)

CROSSREFS

Cf. A194647, A173783, A137432.

Sequence in context: A321817 A231305 A108538 * A221753 A055867 A304346

Adjacent sequences:  A195590 A195591 A195592 * A195594 A195595 A195596

KEYWORD

nonn

AUTHOR

Vaclav Kotesovec, Sep 21 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 September 22 02:48 EDT 2021. Contains 347605 sequences. (Running on oeis4.)