A155601 a(n) = 10^n - 2^n + 1^n.

1, 9, 97, 993, 9985, 99969, 999937, 9999873, 99999745, 999999489, 9999998977, 99999997953, 999999995905, 9999999991809, 99999999983617, 999999999967233, 9999999999934465, 99999999999868929, 999999999999737857, 9999999999999475713, 99999999999998951425

Offset: 0

Author

Mohammad K. Azarian, Jan 25 2009

Keywords

• nonn
• easy

Links

• Index entries for linear recurrences with constant coefficients, signature (13,-32,20).

Crossrefs

Cf. A074501, A020515, A155588, A155590, A155592, A155593, A155594, A155596, A155597, A155598, A155599, A155600.

Programs

Mathematica

Table[10^n-2^n+1,{n,0,20}] (* or *) LinearRecurrence[{13,-32,20},{1,9,97},20] (* Harvey P. Dale, Jan 13 2022 *)

PARI

a(n)=10^n-2^n+1 \\ Charles R Greathouse IV, Sep 24 2015

Formula

G.f.: 1/(1-10*x)-1/(1-2*x)+1/(1-x).

E.g.f.: e^(10*x)-e^(2*x)+e^x.

a(n) = 12*a(n-1)-20*a(n-2)+9 with a(0)=1, a(1)=9. - Vincenzo Librandi, Jul 21 2010

a(n) = A060458(n)+1. - R. J. Mathar, Mar 10 2022