OFFSET
0,2
COMMENTS
Trinomial transform of Jacobsthal numbers A001045. - Paul Barry, Sep 10 2007
LINKS
Nathaniel Johnston, Table of n, a(n) for n = 0..250
Index entries for linear recurrences with constant coefficients, signature (8,-7).
FORMULA
a(n) = (2*7^n + 1)/3.
G.f.: (1-3*x)/((1-x)*(1-7*x)).
E.g.f.: (2*exp(7*x) + exp(x))/3.
a(n) = Sum_{k=0..2*n} trinomial(n,k)*Fibonacci(k+1), where trinomial(n,k) are the trinomial coefficients (A027907). - Paul Barry, Sep 10 2007
a(n) = 7*a(n-1) - 2, a(n) = 8*a(n-1) - 7*a(n-2). - Vincenzo Librandi, Nov 06 2011
MAPLE
seq((2*7^n+1)/3, n=0..20); # Nathaniel Johnston, Jun 26 2011
PROG
(Magma) [(2*7^n+1)/3: n in [0..30]]; // Vincenzo Librandi, Nov 06 2011
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Paul Barry, Apr 23 2003
STATUS
approved