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A155648
a(n) = 10^n + 6^n - 1.
20
1, 15, 135, 1215, 11295, 107775, 1046655, 10279935, 101679615, 1010077695, 10060466175, 100362797055, 1002176782335, 10013060694015, 100078364164095, 1000470184984575, 10002821109907455, 100016926659444735
OFFSET
0,2
FORMULA
G.f.: 1/(1-10*x) + 1/(1-6*x) - 1/(1-x).
E.g.f.: e^(10*x) + e^(6*x) - e^x.
a(n) = 16*a(n-1) - 60*a(n-2) - 45; a(0)=1, a(1)=15. - Vincenzo Librandi, Jul 21 2010
a(n) = 17*a(n-1) - 76*a(n-2) + 60*a(n-3); a(0)=1, a(1)=15, a(2)=135. - Harvey P. Dale, Mar 30 2014
MATHEMATICA
Table[10^n+6^n-1, {n, 0, 20}] (* or *) LinearRecurrence[{17, -76, 60}, {1, 15, 135}, 20] (* Harvey P. Dale, Mar 30 2014 *)
PROG
(PARI) a(n)=10^n+6^n-1 \\ Charles R Greathouse IV, Sep 24 2015
(Magma) [10^n + 6^n - 1 : n in [0..20]]; // Wesley Ivan Hurt, Jan 06 2024
KEYWORD
nonn,easy
AUTHOR
Mohammad K. Azarian, Jan 31 2009
STATUS
approved