A175602 a(n) = 8*(10^n - 3).

56, 776, 7976, 79976, 799976, 7999976, 79999976, 799999976, 7999999976, 79999999976, 799999999976, 7999999999976, 79999999999976, 799999999999976, 7999999999999976, 79999999999999976, 799999999999999976, 7999999999999999976, 79999999999999999976, 799999999999999999976

Offset

1,1

Links

Vincenzo Librandi, Table of n, a(n) for n = 1..100

Index entries for linear recurrences with constant coefficients, signature (11,-10).

Formula

From Vincenzo Librandi, Aug 23 2014: (Start)

G.f.: 8*x*(7 + 20*x)/((1 - x)*(1 - 10*x)).

a(n) = 11*a(n-1) - 10*a(n-2). (End)

From Elmo R. Oliveira, Dec 03 2025: (Start)

E.g.f.: 8*(2 - 3*exp(x) + exp(10*x)).

a(n) = 8*A173833(n) = 4*A086946(n) = 2*A177108(n). (End)

Mathematica

Table[8 (10^n - 3), {n, 20}] (* or *) CoefficientList[Series[8 (7 + 20 x)/((1 - x) (1 - 10 x)), {x, 0, 20}], x] (* Vincenzo Librandi, Aug 23 2014 *)
LinearRecurrence[{11, -10}, {56, 776}, 20] (* Harvey P. Dale, Sep 26 2018 *)

Prog

(Magma) [8*(10^n-3): n in [1..20]]; // Vincenzo Librandi, Aug 23 2014

Crossrefs

Cf. A086946, A173833, A177108.

Sequence in context: A201098 A190419 A105940 * A227059 A383640 A285155

Adjacent sequences: A175599 A175600 A175601 * A175603 A175604 A175605

Keyword

nonn,easy

Author

Vincenzo Librandi

Status

approved