A155661 a(n) = 10^n - 7^n + 1.

1, 4, 52, 658, 7600, 83194, 882352, 9176458, 94235200, 959646394, 9717524752, 98022673258, 986158712800, 9903110989594, 99321776927152, 995252438490058, 9966767069430400, 99767369486012794, 998371586402089552

Offset: 0

Author

Mohammad K. Azarian, Jan 31 2009

Keywords

• nonn
• easy

Links

• Index entries for linear recurrences with constant coefficients, signature (18,-87,70).

Crossrefs

Cf. A155638, A155639, A155640, A155641, A155642, A155643, A155644, A155645, A155646, A155647, A155648, A155649, A155650, A155651, A155652, A155653, A155654, A155655, A155656, A155657, A155658, A155659, A155660.

Programs

Mathematica

Table[10^n-7^n+1,{n,0,20}] (* or *) LinearRecurrence[{18,-87,70},{1,4,52}, 21] (* Harvey P. Dale, May 05 2011 *)

PARI

a(n)=10^n-7^n+1 \\ Charles R Greathouse IV, Jun 11 2015

Formula

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

E.g.f.: e^(10*x)-e^(7*x)+e^x.

a(n) = 17*a(n-1)-70*a(n-2)+54 with a(0)=1, a(1)=4. - Vincenzo Librandi, Jul 21 2010

a(0)=1, a(1)=4, a(2)=52, a(n)=18*a(n-1)-87*a(n-2)+70*a(n-3). - Harvey P. Dale, May 05 2011