OFFSET
0,1
LINKS
Nathaniel Johnston, Table of n, a(n) for n = 0..250
Index entries for linear recurrences with constant coefficients, signature (0,130,0,-1).
FORMULA
a(n) = 16*a(n-1) + a(n-2) for n>=2 even and a(n) = 8*a(n-1) + a(n-2) for n >= 2 odd. - Nathaniel Johnston, Jun 26 2011
From Colin Barker, Feb 28 2013: (Start)
a(n) = 130*a(n-2) - a(n-4).
G.f.: -(x^3-8*x^2-65*x-8) / (x^4-130*x^2+1). (End)
MAPLE
a := proc(n) option remember: if(n<=1)then return n+8^(n+1): fi: if(n mod 2 = 0)then return 16*a(n-1) + a(n-2): else return 8*a(n-1) + a(n-2): fi: end: seq(a(n), n=0..17); # Nathaniel Johnston, Jun 26 2011
MATHEMATICA
Numerator[Convergents[Sqrt[66], 30]] (* or *) LinearRecurrence[{0, 130, 0, -1}, {8, 65, 1048, 8449}, 30] (* Harvey P. Dale, Jan 31 2023 *)
CROSSREFS
KEYWORD
nonn,cofr,frac,easy
AUTHOR
STATUS
approved