A199021 a(n) = (5*11^n - 1)/2.

2, 27, 302, 3327, 36602, 402627, 4428902, 48717927, 535897202, 5894869227, 64843561502, 713279176527, 7846070941802, 86306780359827, 949374583958102, 10443120423539127, 114874324658930402, 1263617571248234427, 13899793283730578702, 152897726121036365727, 1681874987331400023002

Offset

0,1

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..900

Index entries for linear recurrences with constant coefficients, signature (12,-11).

Formula

a(n) = 11*a(n-1) + 5.

a(n) = 12*a(n-1) - 11*a(n-2), n > 1.

G.f.: (2 + 3*x)/(1 - 12*x + 11*x^2). - Vincenzo Librandi, Jan 04 2013

From Elmo R. Oliveira, Apr 02 2025: (Start)

E.g.f.: exp(x)*(5*exp(10*x) - 1)/2.

a(n) = A199022(n)/2. (End)

Mathematica

CoefficientList[Series[(2 + 3*x)/(1 - 12*x + 11*x^2), {x, 0, 30}], x] (* Vincenzo Librandi, Jan 04 2013 *)
LinearRecurrence[{12, -11}, {2, 27}, 20] (* Harvey P. Dale, Aug 13 2018 *)

Prog

(Magma) [(5*11^n-1)/2 : n in [0..20]];

Crossrefs

Cf. A199022.

Sequence in context: A011543 A221186 A220530 * A091709 A083384 A121971

Adjacent sequences: A199018 A199019 A199020 * A199022 A199023 A199024

Keyword

nonn,easy

Author

Vincenzo Librandi, Nov 02 2011

Status

approved