OFFSET
0,1
LINKS
Tanya Khovanova, Recursive Sequences
Index entries for linear recurrences with constant coefficients, signature (1, 1).
FORMULA
From Alois P. Heinz, Jul 31 2008: (Start)
G.f.: (4+11*x)/(1-x-x^2).
a(n) = term (1,1) in the 1 X 2 matrix [4,11] . [1,1; 1,0]^n. (End)
MAPLE
a:= n-> (Matrix([[4, 11]]).Matrix([[1, 1], [1, 0]])^n)[1, 1]:
seq(a(n), n=0..35); # Alois P. Heinz, Jul 31 2008
MATHEMATICA
a={}; b=4; c=15; AppendTo[a, b]; AppendTo[a, c]; Do[b=b+c; AppendTo[a, b]; c=b+c; AppendTo[a, c], {n, 1, 40, 1}]; a (* Vladimir Joseph Stephan Orlovsky, Jul 23 2008 *)
Transpose[NestList[{#[[2]], #[[2]]+#[[1]]}&, {4, 15}, 40]][[1]] (* Harvey P. Dale, Dec 12 2010 *)
LinearRecurrence[{1, 1}, {4, 15}, 40] (* Jean-François Alcover, Feb 14 2016 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved