a(n) = 3*a(n-1) + 3*a(n-2) - a(n-3); a(0) = 1, a(1) = 0, a(2) = 3. a(n) = 4*{a(n-1)+(-1)^n}-a(n-2); a(0) = 1, a(1) = 0.

A120892

a(n) = 3*a(n-1) + 3*a(n-2) - a(n-3); a(0) = 1, a(1) = 0, a(2) = 3. a(n) = 4*{a(n-1)+(-1)^n}-a(n-2); a(0) = 1, a(1) = 0.

Terms

    a(0) =1a(1) =0a(2) =3a(3) =8a(4) =33a(5) =120a(6) =451a(7) =1680a(8) =6273a(9) =23408a(10) =87363a(11) =326040a(12) =1216801a(13) =4541160a(14) =16947843a(15) =63250208a(16) =236052993a(17) =880961760a(18) =3287794051a(19) =12270214440a(20) =45793063713a(21) =170902040408a(22) =637815097923

External references