OFFSET
1,1
COMMENTS
Also n - 1 ones followed by a nine.
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..100
Markus Tervooren, Factorizations of (1)w9
Index entries for linear recurrences with constant coefficients, signature (11, -10).
FORMULA
G.f.: x*(9 - 80*x)/((1 - x)*(1 - 10*x)). - Vincenzo Librandi, Apr 26 2014
MATHEMATICA
Table[FromDigits[PadLeft[{9}, n, 1]], {n, 20}] (* Harvey P. Dale, Apr 25 2014 *)
CoefficientList[Series[(9 - 80 x)/((1 - x) (1 - 10 x)), {x, 0, 30}], x] (* Vincenzo Librandi, Apr 26 2014 *)
(10^Range[20] + 71)/9 (* Alonso del Arte, Apr 18 2015 *)
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Ivan Panchenko, Sep 10 2009
STATUS
approved