OFFSET
0,1
LINKS
Colin Barker, Table of n, a(n) for n = 0..1000
Boothby, T.; Burkert, J.; Eichwald, M.; Ernst, D. C.; Green, R. M.; Macauley, M. On the cyclically fully commutative elements of Coxeter groups, J. Algebr. Comb. 36, No. 1, 123-148 (2012) Table 1 CFC Type D.
Index entries for linear recurrences with constant coefficients, signature (3,-1).
FORMULA
PROG
(PARI) a(n) = 4*fibonacci(2*n+1) + 5*fibonacci(2*n)
(PARI) Vec((4+x)/(1-3*x+x^2) + O(x^50))
(Magma) k:=4; [k*Fibonacci(2*n+1)+(k+1)*Fibonacci(2*n): n in [0..30]]; // Bruno Berselli, Apr 06 2016
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Colin Barker, Apr 05 2016
EXTENSIONS
Changed offset and adapted definition, programs and formulas by Bruno Berselli, Apr 06 2016
STATUS
approved