A172525 9*n*12345679.

111111111, 222222222, 333333333, 444444444, 555555555, 666666666, 777777777, 888888888, 999999999, 1111111110, 1222222221, 1333333332, 1444444443, 1555555554, 1666666665, 1777777776, 1888888887, 1999999998, 2111111109

Offset

1,1

Links

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

Index entries for linear recurrences with constant coefficients, signature (2,-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

Adjacent sequences: A172522 A172523 A172524 * A172526 A172527 A172528

Keyword

nonn,easy

Author

Vincenzo Librandi, Feb 06 2010

Status

approved