A276352 a(n) = 100^n - 10^n.

0, 90, 9900, 999000, 99990000, 9999900000, 999999000000, 99999990000000, 9999999900000000, 999999999000000000, 99999999990000000000, 9999999999900000000000, 999999999999000000000000, 99999999999990000000000000, 9999999999999900000000000000, 999999999999999000000000000000

Offset

0,2

Links

Table of n, a(n) for n=0..15.

Index entries for linear recurrences with constant coefficients, signature (110,-1000).

Formula

a(n) = floor((1000^n)/(10^n + 1)).

a(n) = A002283(n)*A011557(n).

a(n) = 9*A138147(n), for n>0.

a(n) = A168624(n) - 1.

a(n) = Sum_{k=1..n} 9*10^(2n-k).

a(n) = ((10^n)*A002283(2n))/(10^n + 1).

From Chai Wah Wu, Sep 01 2016: (Start)

a(n) = 110*a(n-1) - 1000*a(n-2) for n > 1.

G.f.: 90*x/((10*x - 1)*(100*x - 1)). (End)

Maple

A276352:=n->100^n-10^n: seq(A276352(n), n=0..20); # Wesley Ivan Hurt, Sep 07 2016

Mathematica

Table[100^n - 10^n, {n, 0, 10}] (* Alonso del Arte, Aug 31 2016 *)

Prog

(PARI) a(n)=100^n-10^n \\ Charles R Greathouse IV, Sep 01 2016
(Magma) [100^n-10^n : n in [0..20]]; // Wesley Ivan Hurt, Sep 07 2016

Crossrefs

Cf. A002283, A011557, A138147, A168624.

Sequence in context: A166804 A116273 A036257 * A203779 A359842 A295594

Adjacent sequences: A276349 A276350 A276351 * A276353 A276354 A276355

Keyword

nonn,easy

Author

Carauleanu Marc, Aug 31 2016

Status

approved