OFFSET
1,3
COMMENTS
All even terms are 0.
LINKS
Index entries for linear recurrences with constant coefficients, signature (0,11,0,0,0,2).
FORMULA
G.f.: x*(1 - 3*x^2 - 2*x^4)/(1 - 11*x^2 - 2*x^6).
a(n) = 11*a(n-2) + 2*a(n-6) for n>6. - Wesley Ivan Hurt, Apr 10 2016
MAPLE
A181689:=proc(n) option remember:
if n mod 2 = 0 then 0 elif n=1 then 1 elif n=3 then 8 elif n=5 then 86 else 11*a(n-2)+2*a(n-6); fi; end: seq(A181689(n), n=1..50); # Wesley Ivan Hurt, Apr 10 2016
MATHEMATICA
CoefficientList[Series[(1 - 3*x^2 - 2*x^4)/(1 - 11*x^2 - 2*x^6), {x, 0, 50}], x] (* Wesley Ivan Hurt, Apr 10 2016 *)
PROG
(Magma) I:=[1, 0, 8, 0, 86, 0]; [n le 6 select I[n] else 11*Self(n-2)+2*Self(n-6): n in [1..50]]; // Wesley Ivan Hurt, Apr 10 2016
(PARI) x='x+O('x^99); Vec(x*(1-3*x^2-2*x^4)/(1-11*x^2-2*x^6)) \\ Altug Alkan, Apr 11 2016
CROSSREFS
KEYWORD
nonn,easy,walk
AUTHOR
Sean A. Irvine, Nov 17 2010
STATUS
approved