A110807 n times largest n-digit number.

0, 9, 198, 2997, 39996, 499995, 5999994, 69999993, 799999992, 8999999991, 99999999990, 1099999999989, 11999999999988, 129999999999987, 1399999999999986, 14999999999999985, 159999999999999984

Offset: 0

Author

Amarnath Murthy, Aug 14 2005

Keywords

• base
• easy
• nonn

Examples

			a(3) = 3*999 = 2997.
		

Links

• G. C. Greubel, Table of n, a(n) for n = 0..990
• Index entries for linear recurrences with constant coefficients, signature (22,-141,220,-100).

Programs

Magma

[n*(10^n-1): n in [1..25]]; // G. C. Greubel, Oct 19 2017

Mathematica

Table[(10^n - 1)*n, {n, 1, 30}] (* Stefan Steinerberger *)
LinearRecurrence[{22,-141,220,-100},{0,9,198,2997,39996},20] (* Harvey P. Dale, Sep 22 2016 *)

PARI

for(n=1,25, print1(n*(10^n-1), ", ")) \\ G. C. Greubel, Oct 19 2017

Formula

a(n) = n*(10^n-1) = 9*A053422(n). - R. J. Mathar, Dec 04 2016

G.f.: -9*x*(-1+10*x^2) / ( (10*x-1)^2*(x-1)^2 ). - R. J. Mathar, Dec 04 2016