OFFSET
0,1
LINKS
Harvey P. Dale, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (2, 2).
FORMULA
a(n) = 2*a(n-1) + 2*a(n-2) for n > 1; a(0) = 5, a(1) = 8.
G.f.: (5-2*x)/(1-2*x-2*x^2).
MATHEMATICA
LinearRecurrence[{2, 2}, {5, 8}, 30] (* Harvey P. Dale, Aug 17 2013 *)
PROG
(Magma) Z<x>:=PolynomialRing(Integers()); N<r>:=NumberField(x^2-3); S:=[ ((5+r)*(1+r)^n+(5-r)*(1-r)^n)/2: n in [0..25] ]; [ Integers()!S[j]: j in [1..#S] ]; // Klaus Brockhaus, Jul 14 2009
CROSSREFS
KEYWORD
nonn
AUTHOR
Al Hakanson (hawkuu(AT)gmail.com), Jul 06 2009
EXTENSIONS
Edited and extended beyond a(5) by Klaus Brockhaus, Jul 14 2009
STATUS
approved