OFFSET
1,2
REFERENCES
R. P. Grimaldi, Ternary strings with no consecutive 0's and no consecutive 1's, Congressus Numerantium, 205 (2011), 129-149. (The sequence desc_n.)
LINKS
Index entries for linear recurrences with constant coefficients, signature (4,-2,-4,-1).
FORMULA
G.f.: x^2*(2*x+3) / (x^2+2*x-1)^2. - Colin Barker, Jul 25 2013
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, Mar 15 2011
STATUS
approved