A173262 a(n) = (2*10^n+61)/9

9, 29, 229, 2229, 22229, 222229, 2222229, 22222229, 222222229, 2222222229, 22222222229, 222222222229, 2222222222229, 22222222222229, 222222222222229, 2222222222222229, 22222222222222229, 222222222222222229

Offset

1,1

Comments

n-1 2's followed by a 9.

Links

Table of n, a(n) for n=1..18.

Markus Tervooren, Factorizations of (2)w9

Index entries for linear recurrences with constant coefficients, signature (11, -10).

Formula

a(n)= 11*a(n-1) -10*a(n-2). G.f.: x*(-9+70*x)/((10*x-1)*(1-x)). [From R. J. Mathar, Feb 21 2010]

a(n)=10*a(n-1)-61, (with a(1)=9) [From Vincenzo Librandi, Feb 24 2010]

Mathematica

Table[10FromDigits[PadRight[{}, n, 2]]+9, {n, 0, 20}] (* or *) LinearRecurrence[ {11, -10}, {9, 29}, 20] (* Harvey P. Dale, Apr 09 2019 *)

Crossrefs

Sequence in context: A146413 A146054 A321588 * A337445 A291159 A104516

Adjacent sequences: A173259 A173260 A173261 * A173263 A173264 A173265

Keyword

easy,nonn

Author

Ivan Panchenko, Feb 14 2010

Extensions

Extended by R. J. Mathar, Feb 21 2010

Status

approved