OFFSET
0,2
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..1000
G. Wu, M. G. Parker, A complementary construction using mutually unbiased bases, arXiv preprint arXiv:1309.0157 [cs.IT], 2013 [See Th. 1].
Index entries for linear recurrences with constant coefficients, signature (6,12,-72).
FORMULA
G.f.: ( 1-2*x-16*x^2 ) / ( (6*x-1)*(12*x^2-1) ). - R. J. Mathar, Dec 04 2013
MAPLE
f:=proc(n)
if (n mod 2) = 0 then 2^n*3^(n-1)+2^(n+1)*3^(n/2-1) else
2^n*3^(n-1)+2^n*3^((n-1)/2) fi; end;
[seq(f(n), n=0..40)];
MATHEMATICA
LinearRecurrence[{6, 12, -72}, {1, 4, 20}, 40] (* Harvey P. Dale, May 03 2017 *)
CoefficientList[Series[(1 - 2 x - 16 x^2)/((6 x - 1) (12 x^2 - 1)), {x, 0, 33}], x] (* Vincenzo Librandi, May 07 2017 *)
PROG
(Magma) I:=[1, 4, 20]; [n le 3 select I[n] else 6*Self(n-1)+12*Self(n-2)-72*Self(n-3): n in [1..30]]; // Vincenzo Librandi, May 07 2017
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Dec 02 2013
STATUS
approved