A146529 A two level sequence: v(n)=2*(If[n == 0, 0, 2^(n - 1)] + 2); a(n)=If[n == 0, 6, (v[n] + v[n - 1] - 2)].

6, 8, 12, 18, 30, 54, 102, 198, 390, 774, 1542, 3078, 6150, 12294, 24582, 49158, 98310, 196614, 393222, 786438, 1572870, 3145734, 6291462, 12582918, 25165830, 50331654, 100663302, 201326598, 402653190, 805306374, 1610612742

Offset: 0

Author

Roger L. Bagula, Oct 30 2008

Keywords

• nonn

Links

• Index entries for linear recurrences with constant coefficients, signature (3,-2).

Programs

Mathematica

v[n_] := 2*(If[n == 0, 0, 2^(n - 1)] + 2); Table[v[n], {n, 0, 30}]; Table[If[n == 0, 6, (v[n] + v[n - 1] - 2)], {n, 0, 30}]

Formula

v(n)=2*(If[n == 0, 0, 2^(n - 1)] + 2); a(n)=If[n == 0, 6, (v[n] + v[n - 1] - 2)].

a(n) = 3*a(n-1)-2*a(n-2), n>4. a(n) = 6+3*2^(n-1) = 6+A007283(n-1), n>1. [From R. J. Mathar, Nov 21 2008]