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!)
A289707 Number of 6-cycles in the n-triangular honeycomb queen graph. 4
0, 0, 16, 911, 8013, 38130, 129932, 358272, 851710, 1815124, 3554910, 6510729, 11289019, 18704640, 29823436, 46014402, 69002190, 100930284, 144424446, 202667301, 279473821, 379377584, 507719550, 670746120, 875712560, 1130992902, 1446199474, 1832304547, 2301777585, 2868718404 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

LINKS

Colin Barker, Table of n, a(n) for n = 1..1000

Eric Weisstein's World of Mathematics, Graph Cycle

Index entries for linear recurrences with constant coefficients, signature (3, 1, -10, 3, 13, -3, -12, -3, 13, 3, -10, 1, 3, -1).

FORMULA

a(n) = 3*a(n-1)+a(n-2)-10*a(n-3)+3*a(n-4)+13*a(n-5)-3*a(n-6)-12*a(n-7)-3*a(n-8)+13*a(n-9)+3*a(n-10)-10*a(n-11)+a(n-12)+3*a(n-13)-a(n-14).

G.f.: x^3*(16 + 863*x + 5264*x^2 + 13340*x^3 + 16591*x^4 + 7535*x^5 - 7572*x^6 - 14592*x^7 - 9919*x^8 - 2886*x^9) / ((1 - x)^8*(1 + x)^4*(1 + x + x^2)). - Colin Barker, Jul 27 2017

MATHEMATICA

Table[(-315 (-1)^n (-2489 + 1659 n - 297 n^2 + 10 n^3) - 792995 + 3789081 n - 1968939 n^2 - 3033450 n^3 + 3489990 n^4 - 1269366 n^5 + 154014 n^6 + 1440 n^7 + 8960 Cos[2 n Pi/3] - 8960 Sqrt[3] Sin[2 n Pi/3])/40320, {n, 20}]

LinearRecurrence[{3, 1, -10, 3, 13, -3, -12, -3, 13, 3, -10, 1, 3, -1}, {0, 0, 16, 911, 8013, 38130, 129932, 358272, 851710, 1815124, 3554910, 6510729, 11289019, 18704640}, 20]

PROG

(PARI) concat(vector(2), Vec(x^3*(16 + 863*x + 5264*x^2 + 13340*x^3 + 16591*x^4 + 7535*x^5 - 7572*x^6 - 14592*x^7 - 9919*x^8 - 2886*x^9) / ((1 - x)^8*(1 + x)^4*(1 + x + x^2)) + O(x^60))) \\ Colin Barker, Jul 27 2017

CROSSREFS

Cf. A105636 (3-cycles), A289705 (4-cycles), A289706 (5-cycles).

Sequence in context: A214386 A185561 A283946 * A006089 A260620 A290940

Adjacent sequences:  A289704 A289705 A289706 * A289708 A289709 A289710

KEYWORD

nonn,easy

AUTHOR

Eric W. Weisstein, Jul 14 2017

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 April 22 14:00 EDT 2021. Contains 343177 sequences. (Running on oeis4.)