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A191465 9^n - 2^n. 2
0, 7, 77, 721, 6545, 59017, 531377, 4782841, 43046465, 387419977, 3486783377, 31381057561, 282429532385, 2541865820137, 22876792438577, 205891132061881, 1853020188786305, 16677181699535497, 150094635296736977, 1350851717672467801 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 0..300

Index entries for linear recurrences with constant coefficients, signature (11,-18).

FORMULA

a(n) = 11*a(n-1) - 18*a(n-2).

G.f.: 7*x/((1-2*x)*(1-9*x)). - Vincenzo Librandi, Oct 04 2014

MATHEMATICA

Table[9^n-2^n, {n, 0, 20}] (* or *) LinearRecurrence[{11, -18}, {0, 7}, 20] (* Harvey P. Dale, Apr 16 2014 *)

CoefficientList[Series[7 x / ((1 - 2 x) (1 - 9 x)), {x, 0, 30}], x] (* Vincenzo Librandi, Oct 04 2014 *)

PROG

(PARI) a(n)=9^n-1<<n \\ Charles R Greathouse IV, Jun 08 2011

CROSSREFS

Cf. A118004, A016185.

Sequence in context: A261741 A228414 A043042 * A229281 A144071 A061546

Adjacent sequences:  A191462 A191463 A191464 * A191466 A191467 A191468

KEYWORD

nonn,easy

AUTHOR

Vincenzo Librandi, Jun 03 2011

STATUS

approved

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Last modified October 19 04:40 EDT 2019. Contains 328211 sequences. (Running on oeis4.)