OFFSET
0,2
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..100
Index entries for linear recurrences with constant coefficients, signature (18,-87,110).
FORMULA
From Vincenzo Librandi, Aug 25 2011: (Start)
a(n) = 18*a(n-1) - 87*a(n-2) + 110*a(n-3); a(1)=1, a(2)=18, a(3)=237.
a(n) = 16*a(n-1) - 55*a(n-2) + 2^n; a(1)=1, a(2)=18. (End)
a(n) = (1/54)*(2*2^(2+n) - 3*5^(2+n) + 11^(2+n)). - Bruno Berselli, Aug 25 2011
MATHEMATICA
CoefficientList[Series[1/((1-2x)(1-5x)(1-11x)), {x, 0, 30}], x] (* or *) LinearRecurrence[{18, -87, 110}, {1, 18, 237}, 30] (* Vincenzo Librandi, Aug 25 2011 *)
PROG
(Magma) [ n eq 1 select 1 else n eq 2 select 18 else n eq 3 select 237 else 18*Self(n-1)-87*Self(n-2) +110*Self(n-3): n in [1..20] ]; // Vincenzo Librandi, Aug 25 2011
(PARI) Vec(1/((1-2*x)*(1-5*x)*(1-11*x))+O(x^18)) \\ Bruno Berselli, Aug 25 2011
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved