A155631 10^n-4^n+1^n

1, 7, 85, 937, 9745, 98977, 995905, 9983617, 99934465, 999737857, 9998951425, 99995805697, 999983222785, 9999932891137, 99999731564545, 999998926258177, 9999995705032705, 99999982820130817, 999999931280523265

Offset

0,2

Links

Table of n, a(n) for n=0..18.

Index entries for linear recurrences with constant coefficients, signature (15,-54,40).

Formula

G.f.: 1/(1-10*x)-1/(1-4*x)+1/(1-x). E.g.f.: e^(10*x)-e^(4*x)+e^x.

a(n)=14*a(n-1)-40*a(n-2)+27 with a(0)=1, a(1)=7 - Vincenzo Librandi, Jul 21 2010

Mathematica

LinearRecurrence[{15, -54, 40}, {1, 7, 85}, 30] (* Harvey P. Dale, Aug 30 2017 *)

Prog

(PARI) a(n)=10^n-4^n+1 \\ Charles R Greathouse IV, Sep 24 2015

Crossrefs

Cf. A155596, A155597, A155598, A155599, A155600, A155601, A155622, A155623, A155624, A155625, A155626, A155627, A155628, A155629, A155630.

Sequence in context: A162160 A027531 A155459 * A126344 A193578 A309187

Adjacent sequences: A155628 A155629 A155630 * A155632 A155633 A155634

Keyword

nonn,easy

Author

Mohammad K. Azarian, Jan 30 2009

Status

approved