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A191466
9^n - 5^n.
2
0, 4, 56, 604, 5936, 55924, 515816, 4704844, 42656096, 385467364, 3477018776, 31332231484, 282185395856, 2540645125204, 22870688939336, 205860614516524, 1852867600961216, 16676418760213444, 150090820599733496, 1350832644186663964
OFFSET
0,2
FORMULA
a(n) = 14*a(n-1) - 45*a(n-2).
G.f.: 4*x/((1-5*x)*(1-9*x)). - Vincenzo Librandi, Oct 05 2014
a(n+1) = 4*A016163(n). - Vincenzo Librandi, Oct 05 2014
MATHEMATICA
Table[9^n - 5^n, {n, 0, 25}] (* or *) CoefficientList[Series[4 x/((1 - 5 x) (1 - 9 x)), {x, 0, 30}], x] (* Vincenzo Librandi, Oct 05 2014 *)
LinearRecurrence[{14, -45}, {0, 4}, 20] (* Harvey P. Dale, Jun 26 2019 *)
PROG
(Magma) [9^n-5^n: n in [0..20]];
(PARI) a(n)=9^n-5^n \\ Charles R Greathouse IV, Jun 08 2011
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Jun 03 2011
STATUS
approved