login
A124351
Order of the automorphism group of the n-prism graph.
1
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
Eric Weisstein's World of Mathematics, Graph Automorphism
Eric Weisstein's World of Mathematics, Prism Graph
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
KEYWORD
nonn,easy
AUTHOR
Eric W. Weisstein, Oct 26 2006
STATUS
approved