OFFSET
1,1
REFERENCES
F. Faase, On the number of specific spanning subgraphs of the graphs G X P_n, Ars Combin. 49 (1998), 129-154.
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..700
F. Faase, On the number of specific spanning subgraphs of the graphs G X P_n, Preliminary version of paper that appeared in Ars Combin. 49 (1998), 129-154.
F. Faase, Results from the counting program
Index entries for linear recurrences with constant coefficients, signature (28,12).
FORMULA
a(n) = 28a(n-1) + 12a(n-2), n>2.
G.f.: 12*x*(12*x^2-12*x-1)/(12*x^2+28*x-1). - Colin Barker, Aug 30 2012
MATHEMATICA
CoefficientList[Series[12 (12 x^2 - 12 x - 1)/(12 x^2 + 28 x - 1), {x, 0, 30}], x] (* Vincenzo Librandi, Oct 14 2013 *)
PROG
(Magma) I:=[12, 480, 13440]; [n le 3 select I[n] else 28*Self(n-1)+12*Self(n-2): n in [1..20]]; // Vincenzo Librandi, Oct 14 2013
(PARI) a(n)=([0, 1; 12, 28]^(n-1)*[12; 480])[1, 1] \\ Charles R Greathouse IV, Jun 23 2020
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved