OFFSET
0,2
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (-4,5).
FORMULA
a(n) = 5*a(n-2) - 4*a(n-1), a(0)= 1, a(1)= 2, for n>1.
a(n) = 7-5*a(n-1), a(0)=1.
a(n) = a(n-1)+(-5)^(n-1), a(0)=1.
O.g.f.: (1+6*x)/(1+4*x-5*x^2).
E.g.f.: (7*exp(x)-exp(-5*x))/6.
MATHEMATICA
LinearRecurrence[{-4, 5}, {1, 2}, 30] (* Harvey P. Dale, Mar 10 2016 *)
Table[(7 - (-5)^n)/6, {n, 24}] (* or *)
CoefficientList[Series[(1 + 6 x)/(1 + 4 x - 5 x^2), {x, 0, 24}], x] (* Michael De Vlieger, Apr 27 2016 *)
CROSSREFS
KEYWORD
sign,easy
AUTHOR
Philippe Deléham, Oct 07 2009
STATUS
approved