OFFSET
2,1
LINKS
Index entries for linear recurrences with constant coefficients, signature (7,-14,8).
FORMULA
a(n) = 2*A006095(n).
From Colin Barker, Aug 15 2014: (Start)
a(n) = (2 - 3*2^n + 4^n)/3.
a(n) = 7*a(n-1) - 14*a(n-2) + 8*a(n-3).
G.f.: -2*x^2 / ((x-1)*(2*x-1)*(4*x-1)). (End)
a(n) = Sum_{k=0...n-2} 2^k*(2^(n-1)-1+2^k). - J. M. Bergot, Mar 21 2018
MATHEMATICA
PROG
(PARI) Vec(-2*x^2 / ((x-1)*(2*x-1)*(4*x-1)) + O(x^100)) \\ Colin Barker, Aug 15 2014
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Clark Kimberling, Dec 31 2011
STATUS
approved