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A173813
2*(10^n-5), n>0.
1
10, 190, 1990, 19990, 199990, 1999990, 19999990, 199999990, 1999999990, 19999999990, 199999999990, 1999999999990, 19999999999990, 199999999999990, 1999999999999990, 19999999999999990, 199999999999999990
OFFSET
1,1
FORMULA
G.f.: x*(10 + 80*x)/((1 - x)*(1 - 10*x)). - Vincenzo Librandi, Aug 20 2014
MATHEMATICA
Table[(2 (10^n - 5)), {n, 1, 20}] (* or *) CoefficientList[Series[(10 + 80 x)/((1 - x) (1 - 10 x)), {x, 0, 20}], x] (* Vincenzo Librandi, Aug 20 2014 *)
LinearRecurrence[{11, -10}, {10, 190}, 20] (* Harvey P. Dale, Aug 20 2023 *)
PROG
(Magma) [2*(10^n-5): n in [1..20]]; // Vincenzo Librandi, Aug 20 2014
CROSSREFS
Sequence in context: A365175 A239765 A006409 * A249643 A056174 A033714
KEYWORD
nonn
STATUS
approved