A027000 a(n) = Lucas(2n+3) - (6n+4).

1, 13, 54, 171, 487, 1324, 3525, 9297, 24418, 64015, 167691, 439128, 1149769, 3010261, 7881102, 20633139, 54018415, 141422212, 370248333, 969322905, 2537720506, 6643838743, 17393795859, 45537548976, 119218851217, 312119004829

Offset

1,2

Links

Nathaniel Johnston, Table of n, a(n) for n = 1..600

Formula

4*F(2n-1) + 7*F(2n) - 6n - 4, with F(n) = A000045(n) (Fibonacci). - Ralf Stephan, Feb 07 2004

G.f. x*(1+8*x-3*x^2) / ((1-x)^2*(1-3*x+x^2)). - Franklin T. Adams-Watters and D. S. McNeil, Dec 16 2011

Mathematica

Table[LucasL[2n + 3] - (6n + 4), {n, 30}] (* Alonso del Arte, Dec 16 2011 *)

Prog

(Magma) [ Lucas(2*n+3) - (6*n+4): n in [1..100]]; // Vincenzo Librandi, Apr 15 2011

Crossrefs

T(2n, n+1), T given by A026998.

Sequence in context: A372756 A195024 A071230 * A198160 A029531 A158485

Adjacent sequences: A026997 A026998 A026999 * A027001 A027002 A027003

Keyword

nonn

Author

Clark Kimberling

Extensions

a(23) - a(26) from Vincenzo Librandi, Apr 15 2011

Status

approved