A124351 Order of the automorphism group of the n-prism graph.

12, 48, 20, 24, 28, 32, 36, 40, 44, 48, 52, 56, 60, 64, 68, 72, 76, 80, 84, 88, 92, 96, 100, 104, 108, 112, 116, 120, 124, 128, 132, 136, 140, 144, 148, 152, 156, 160, 164, 168, 172, 176, 180, 184, 188, 192, 196, 200, 204, 208, 212, 216, 220, 224, 228, 232, 236

Offset

3,1

Links

G. C. Greubel, Table of n, a(n) for n = 3..5000

Eric Weisstein's World of Mathematics, Graph Automorphism

Eric Weisstein's World of Mathematics, Prism Graph

Index entries for linear recurrences with constant coefficients, signature (2,-1).

Formula

a(4) = 48, otherwise a(n) = 4*n.

G.f.: 12*x^3 + 48*x^4 + 4*x^5*(5-4*x)/(1-x)^2. - R. J. Mathar, Jan 25 2016

E.g.f.: 4*x*(-3 - 3*x + x^3 + 3*exp(x))/3. - G. C. Greubel, May 31 2019

Mathematica

LinearRecurrence[{2, -1}, {12, 48, 20, 24}, 60] (* Vincenzo Librandi, Jan 26 2016 *)

Prog

(PARI) Vec(12*x^3+48*x^4+4*x^5*(5-4*x)/(1-x)^2 + O(x^60)) \\ Altug Alkan, Jan 25 2016
(Magma) I:=[12, 48, 20, 24]; [n le 4 select I[n] else 2*Self(n-1)-Self(n-2): n in [1..60]]; // Vincenzo Librandi, Jan 26 2016
(Sage) a=(12*x^3 + 48*x^4 + 4*x^5*(5-4*x)/(1-x)^2).series(x, 60).coefficients(x, sparse=False); a[3:] # G. C. Greubel, May 31 2019

Crossrefs

Sequence in context: A030623 A030624 A002612 * A335101 A230919 A181925

Adjacent sequences: A124348 A124349 A124350 * A124352 A124353 A124354

Keyword

nonn,easy

Author

Eric W. Weisstein, Oct 26 2006

Status

approved