OFFSET
1,1
LINKS
FORMULA
G.f 9*x*(1+20*x) / ( (10*x-1)*(x-1) ). a(n) = 9*A033175(n-1). - R. J. Mathar, Jan 06 2011
MATHEMATICA
3(10^Range[20]-7) (* or *) LinearRecurrence[{11, -10}, {9, 279}, 20] (* Harvey P. Dale, Mar 20 2020 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Nov 15 2010
STATUS
approved