OFFSET
0,2
REFERENCES
R. P. Grimaldi, Ternary strings with no consecutive 0's and no consecutive 1's, Congressus Numerantium, 205 (2011), 129-149. (See the foot of page 136.)
LINKS
Paolo Xausa, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (4,-2,-4,-1).
FORMULA
G.f.: (1+x)(1-x^2)/(1-2*x-x^2)^2.
a(n) = A000129(n) + (n+1)*A000129(n+1) where A000129 are the Pell numbers. [Corrected by Paolo Xausa, Feb 08 2024]
EXAMPLE
a(3)/A088211(3) = [2;2,2,4] = 53/22.
MATHEMATICA
LinearRecurrence[{4, -2, -4, -1}, {1, 5, 17, 53}, 30] (* Paolo Xausa, Feb 08 2024 *)
CROSSREFS
KEYWORD
frac,nonn
AUTHOR
Paul D. Hanna, Sep 23 2003
STATUS
approved