A083227 a(n) = (9*10^n + (-10)^n)/10.

1, 8, 100, 800, 10000, 80000, 1000000, 8000000, 100000000, 800000000, 10000000000, 80000000000, 1000000000000, 8000000000000, 100000000000000, 800000000000000, 10000000000000000, 80000000000000000

Offset

0,2

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..200

Index entries for linear recurrences with constant coefficients, signature (0,100).

Formula

a(n) = (9*10^n + (-10)^n)/10.

G.f.: (1+8*x)/((1+10*x)*(1-10*x)).

E.g.f.: (9*exp(10*x) + exp(-10*x))/10.

Mathematica

LinearRecurrence[{0, 100}, {1, 8}, 20] (* Harvey P. Dale, Jun 02 2019 *)

Prog

(Magma) [(9*10^n+(-10)^n)/10: n in [0..25]]; // Vincenzo Librandi, Jun 29 2011
(PARI) a(n)= (9*10^n+(-10)^n)/10 \\ Charles R Greathouse IV, Jun 29 2011

Crossrefs

Cf. A083226.

Sequence in context: A316870 A181034 A324067 * A261742 A222486 A229282

Adjacent sequences: A083224 A083225 A083226 * A083228 A083229 A083230

Keyword

easy,nonn

Author

Paul Barry, Apr 23 2003

Status

approved