A173835 10^n+2*n.

1, 12, 104, 1006, 10008, 100010, 1000012, 10000014, 100000016, 1000000018, 10000000020, 100000000022, 1000000000024, 10000000000026, 100000000000028, 1000000000000030, 10000000000000032, 100000000000000034

Offset

0,2

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..100

Index entries for linear recurrences with constant coefficients, signature (12,-21,10).

Formula

G.f.: (1-19*x^2)/((1-x)^2*(1-10*x)). - Vincenzo Librandi, Jul 06 2012

a(n) = 11*a(n-1) -10*a(n-2) -18. - Vincenzo Librandi, Jul 06 2012

Mathematica

CoefficientList[Series[(1-19*x^2)/((1-x)^2*(1-10*x)), {x, 0, 40}], x] (* Vincenzo Librandi, Jul 06 2012 *)
LinearRecurrence[{12, -21, 10}, {1, 12, 104}, 20] (* Harvey P. Dale, Dec 01 2015 *)

Prog

(Magma) I:=[1, 12]; [n le 2 select I[n] else 11*Self(n-1)-10*Self(n-2)-18: n in [1..20]]; // Vincenzo Librandi, Jul 06 2012

Crossrefs

Sequence in context: A222540 A279301 A003431 * A334168 A220111 A353549

Adjacent sequences: A173832 A173833 A173834 * A173836 A173837 A173838

Keyword

nonn,easy

Author

Vincenzo Librandi, Feb 26 2010

Status

approved