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A024115 10^n-n. 10
1, 9, 98, 997, 9996, 99995, 999994, 9999993, 99999992, 999999991, 9999999990, 99999999989, 999999999988, 9999999999987, 99999999999986, 999999999999985, 9999999999999984, 99999999999999983, 999999999999999982 (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 (12,-21,10).

FORMULA

G.f.: (1-3*x+11*x^2)/((1-10*x)*(1-x)^2). - Vincenzo Librandi, Jun 17 2013

a(n) = 12*a(n-1)-21*a(n-2)+10*a(n-3). - Vincenzo Librandi, Jun 17 2013

MATHEMATICA

Table[10^n - n, {n, 0, 20}] (* or *) CoefficientList[Series[(1 - 3 x + 11 x^2) / ((1 - 10 x) (1 - x)^2), {x, 0, 30}], x] (* Vincenzo Librandi, Jun 17 2013 *)

PROG

(MAGMA) [10^n-n: n in [0..20]]; // Vincenzo Librandi, Jun 30 2011

(MAGMA) I:=[1, 9, 98]; [n le 3 select I[n] else 12*Self(n-1)-21*Self(n-2)+10*Self(n-3): n in [1..30]]; // Vincenzo Librandi, Jun 17 2013

(PARI) a(n)=10^n-n \\ Charles R Greathouse IV, Oct 07 2015

CROSSREFS

Cf. numbers of the form k^n-n: A000325 (k=2), A024024 (k=3), A024037 (k=4), A024050 (k=5), A024063 (k=6), A024076 (k=7), A024089 (k=8), A024102 (k=9), this sequence (k=10), A024128 (k=11), A024141 (k=12).

Sequence in context: A064617 A225608 A220490 * A066557 A289214 A121706

Adjacent sequences:  A024112 A024113 A024114 * A024116 A024117 A024118

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane.

STATUS

approved

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Last modified February 16 21:26 EST 2020. Contains 331975 sequences. (Running on oeis4.)