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A199686
6*10^n+1.
2
7, 61, 601, 6001, 60001, 600001, 6000001, 60000001, 600000001, 6000000001, 60000000001, 600000000001, 6000000000001, 60000000000001, 600000000000001, 6000000000000001, 60000000000000001, 600000000000000001, 6000000000000000001
OFFSET
0,1
FORMULA
a(n) = 10*a(n-1)-9.
a(n) = 11*a(n-1)-10*a(n-2).
G.f.: (7-16*x)/((1-x)*(1-10*x)).
MATHEMATICA
6*10^Range[0, 20]+1 (* or *) LinearRecurrence[{11, -10}, {7, 61}, 20] (* Harvey P. Dale, Oct 23 2024 *)
PROG
(Magma) [6*10^n+1: n in [0..30]];
CROSSREFS
Sequence in context: A218473 A098659 A269731 * A113718 A177132 A364430
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Nov 09 2011
STATUS
approved