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A155669
10^n+9^n-1.
5
1, 18, 180, 1728, 16560, 159048, 1531440, 14782968, 143046720, 1387420488, 13486784400, 131381059608, 1282429536480, 12541865828328, 122876792454960, 1205891132094648, 11853020188851840, 116677181699666568
OFFSET
0,2
FORMULA
G.f.: 1/(1-10*x)+1/(1-9*x)-1/(1-x). E.g.f.: e^(10*x)+e^(9*x)-e^x.
a(n)=19*a(n-1)-90*a(n-2)-72 with a(0)=1, a(1)=18 - Vincenzo Librandi, Jul 21 2010
PROG
(PARI) a(n)=10^n+9^n-1 \\ Charles R Greathouse IV, Jun 11 2015
KEYWORD
nonn,easy
AUTHOR
Mohammad K. Azarian, Feb 01 2009
STATUS
approved