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

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 56th year, we are closing in on 350,000 sequences, and we’ve crossed 9,700 citations (which often say “discovered thanks to the OEIS”).

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A289864 Number of cliques in the n-triangular honeycomb queen graph. 0
 2, 8, 27, 72, 169, 367, 764, 1553, 3120, 6234, 12433, 24790, 49451, 98705, 197130, 393879, 787258, 1573876, 3146951, 6292916, 12584637, 25167843, 50333992, 100665997, 201329684, 402656702, 805310349, 1610617218, 3221230495, 6442456549, 12884908118, 25769810675 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Here, cliques means any complete subgraph (not just of maximum size). LINKS Eric Weisstein's World of Mathematics, Clique Index entries for linear recurrences with constant coefficients, signature (5, -8, 2, 7, -7, 2). FORMULA a(n) = (4*n^3 - 18*n^2 - 68*n - 79 - (-1)^n + 3*2^(n + 5))/16. a(n) = 5*a(n-10-8*a(n-2)+2*a(n-3)+7*a(n-4)-7*a(n-5)+2*a(n-6). G.f.: (x*(-2 + 2*x - 3*x^2 + 3*x^3 + 5*x^4 - 2*x^5))/((-1 + x)^4*(-1 + x + 2*x^2)). MATHEMATICA Table[(4 n^3 - 18 n^2 - 68 n - 79 - (-1)^n + 3 2^(n + 5))/16, {n, 20}] LinearRecurrence[{5, -8, 2, 7, -7, 2}, {2, 8, 27, 72, 169, 367}, 20] CoefficientList[Series[(-2 + 2 x - 3 x^2 + 3 x^3 + 5 x^4 - 2 x^5)/((-1 + x)^4 (-1 + x + 2 x^2)), {x, 0, 20}], x] CROSSREFS Sequence in context: A347595 A184628 A092071 * A290056 A100505 A102759 Adjacent sequences:  A289861 A289862 A289863 * A289865 A289866 A289867 KEYWORD nonn,easy AUTHOR Eric W. Weisstein, Jul 13 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.

Last modified December 7 22:50 EST 2021. Contains 349590 sequences. (Running on oeis4.)