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A172525
9*n*12345679.
1
111111111, 222222222, 333333333, 444444444, 555555555, 666666666, 777777777, 888888888, 999999999, 1111111110, 1222222221, 1333333332, 1444444443, 1555555554, 1666666665, 1777777776, 1888888887, 1999999998, 2111111109
OFFSET
1,1
FORMULA
a(n) = 2*a(n-1)-a(n-2). - Colin Barker, Aug 20 2014
G.f.: 111111111*x / (x-1)^2. - Colin Barker, Aug 20 2014
MATHEMATICA
Table[9 n 12345679, {n, 1, 20}] (* Vincenzo Librandi, Aug 20 2014 *)
LinearRecurrence[{2, -1}, {111111111, 222222222}, 20] (* Harvey P. Dale, Sep 10 2023 *)
PROG
(Magma) [9*n*12345679: n in [1..20]]; // Vincenzo Librandi, Aug 20 2014
(PARI) Vec(111111111*x/(x-1)^2 + O(x^100)) \\ Colin Barker, Aug 20 2014
CROSSREFS
Cf. A021085.
Sequence in context: A094327 A180513 A202174 * A038451 A202082 A262499
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Feb 06 2010
STATUS
approved