A198767 8*5^n-1.

7, 39, 199, 999, 4999, 24999, 124999, 624999, 3124999, 15624999, 78124999, 390624999, 1953124999, 9765624999, 48828124999, 244140624999, 1220703124999, 6103515624999, 30517578124999, 152587890624999, 762939453124999

Offset

0,1

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..1000

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

Formula

a(n) = 5*a(n-1)+4.

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

G.f.: (7 - 3*x)/(1 - 6*x + 5*x^2). - Vincenzo Librandi, Jan 04 2013

Mathematica

CoefficientList[Series[(7 - 3*x)/(1 - 6*x + 5*x^2), {x, 0, 30}], x] (* Vincenzo Librandi, Jan 04 2013 *)

Prog

(Magma) [8*5^n-1: n in [0..30]];

Crossrefs

Cf. A024049, A057651, A081655.

Sequence in context: A004057 A081898 A034267 * A026752 A026379 A026708

Adjacent sequences: A198764 A198765 A198766 * A198768 A198769 A198770

Keyword

nonn,easy

Author

Vincenzo Librandi, Oct 30 2011

Status

approved