A047850 a(n) = (5^n + 3)/4.

1, 2, 7, 32, 157, 782, 3907, 19532, 97657, 488282, 2441407, 12207032, 61035157, 305175782, 1525878907, 7629394532, 38146972657, 190734863282, 953674316407, 4768371582032, 23841857910157, 119209289550782, 596046447753907

Offset

0,2

Links

Table of n, a(n) for n=0..22.

Index entries for linear recurrences with constant coefficients, signature (6,-5).

Formula

a(n) = A047848(2,n).

From Philippe Deléham, Oct 06 2009: (Start)

a(n) = 6*a(n-1) - 5*a(n-2) for n > 1.

G.f.: (1-4*x)/((1-x)*(1-5*x)). (End)

a(n) = 5*a(n-1) - 3 (with a(0)=1). - Vincenzo Librandi, Aug 06 2010

From Elmo R. Oliveira, Dec 10 2023: (Start)

a(n) = A132079(n)/2.

E.g.f.: (1/4)*(exp(5*x) + 3*exp(x)). (End)

Prog

(PARI) a(n)=(5^n+3)/4 \\ Charles R Greathouse IV, Oct 07 2015

Crossrefs

Cf. A047848, A132079.

Sequence in context: A327214 A334855 A334854 * A201373 A168494 A181376

Adjacent sequences: A047847 A047848 A047849 * A047851 A047852 A047853

Keyword

nonn,easy

Author

Clark Kimberling

Extensions

Better description from Michael Somos

Status

approved