A108143 a(n)= 5*a(n-1) -a(n-2) -a(n-3).

1, 1, 1, 3, 13, 61, 289, 1371, 6505, 30865, 146449, 694875, 3297061, 15643981, 74227969, 352198803, 1671122065, 7929183553, 37622596897, 178512678867, 847011613885, 4018922793661, 19069089675553, 90479513970219

Offset

0,4

References

Roger Bagula, Factoring Double Fibonacci Sequences, 2000

Links

Table of n, a(n) for n=0..23.

Index entries for linear recurrences with constant coefficients, signature (5,-1,-1)

Formula

G.f.: (1-4*x-3*x^2)/(1-5*x+x^2+x^3) [Sep 28 2009]

Mathematica

F[1] = 1; F[2] = 1; F[3] = 1; F[n__] := F[n] = 5*F[n - 1] - F[n - 2] - F[n - 3] a = Table[Abs[F[n]], {n, 1, 50}]
LinearRecurrence[{5, -1, -1}, {1, 1, 1}, 30] (* Harvey P. Dale, Jan 21 2023 *)

Crossrefs

Cf. A056015, A056016.

Sequence in context: A334150 A239995 A319924 * A101368 A341250 A026704

Adjacent sequences: A108140 A108141 A108142 * A108144 A108145 A108146

Keyword

nonn,easy

Author

Roger L. Bagula, Jun 05 2005

Extensions

Definition replaced by recurrence by the Associate Editors of the OEIS, Sep 28 2009

Status

approved