OFFSET
0,1
COMMENTS
From Tanya Khovanova, Jan 06 2023: (Start)
Fibonacci(6n+3) are divisible by 2 but not by 4.
These numbers are not divisible by 3. (End)
LINKS
FORMULA
From R. J. Mathar, Apr 17 2011: (Start)
G.f.: (2-2*x) / (1 - 18*x + x^2).
a(n) = 2*A007805(n). (End)
a(n) = 2*(S(n, 18) - S(n-1, 18)), n >= 0, with the Chebyshev S-polynomials S(n-1, 18) = A049660(n). (See the g.f.) - Wolfdieter Lang, Jul 10 2018
MATHEMATICA
Table[Fibonacci[6n+3], {n, 0, 30}]
LinearRecurrence[{18, -1}, {2, 34}, 20] (* Harvey P. Dale, Jul 28 2018 *)
PROG
(Magma) [Fibonacci(6*n +3): n in [0..100]]; // Vincenzo Librandi, Apr 17 2011
(PARI) a(n)=fibonacci(6*n+3) \\ Charles R Greathouse IV, Jun 11 2015
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Artur Jasinski, Oct 28 2007
EXTENSIONS
Index in definition and offset corrected by R. J. Mathar, Apr 17 2011
STATUS
approved