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A155631
10^n-4^n+1^n
19
1, 7, 85, 937, 9745, 98977, 995905, 9983617, 99934465, 999737857, 9998951425, 99995805697, 999983222785, 9999932891137, 99999731564545, 999998926258177, 9999995705032705, 99999982820130817, 999999931280523265
OFFSET
0,2
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
KEYWORD
nonn,easy
AUTHOR
Mohammad K. Azarian, Jan 30 2009
STATUS
approved