Convolution of Jacobsthal(n) and 3^n.

Terms

a(0) =0a(1) =1a(2) =4a(3) =15a(4) =50a(5) =161a(6) =504a(7) =1555a(8) =4750a(9) =14421a(10) =43604a(11) =131495a(12) =395850a(13) =1190281a(14) =3576304a(15) =10739835a(16) =32241350a(17) =96767741a(18) =290390604a(19) =871346575a(20) =2614389250a(21) =7843866801a(22) =23532998504a(23) =70601791715a(24) =211810967550a(25) =635444087461