A173834 a(n)=10^n-2*n

1, 8, 96, 994, 9992, 99990, 999988, 9999986, 99999984, 999999982, 9999999980, 99999999978, 999999999976, 9999999999974, 99999999999972, 999999999999970, 9999999999999968, 99999999999999966, 999999999999999964

Offset

0,2

Links

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

Index entries for linear recurrences with constant coefficients, signature (12,-21,10).

Formula

G.f.: (1-4*x+21*x^2)/((1-x)^2*(1-10*x)). - Vincenzo Librandi, Jul 15 2012

a(n) = 10*a(n-1) +18*n -38 = 12*a(n-1) -21*a(n-2) +10*a(n-3). - Vincenzo Librandi, Jul 15 2012

Mathematica

CoefficientList[Series[(1-4*x+21*x^2)/((1-x)^2*(1-10*x)), {x, 0, 30}], x] (* Vincenzo Librandi, Jul 15 2012 *)

Prog

(Magma) [10^n-2*n: n in [0..20]]; // Vincenzo Librandi, Jul 15 2012

Crossrefs

Sequence in context: A099675 A211345 A060458 * A260627 A098430 A365847

Adjacent sequences: A173831 A173832 A173833 * A173835 A173836 A173837

Keyword

nonn,easy

Author

Vincenzo Librandi, Feb 26 2010

Status

approved