Inverse Weigh transform of 3^n.

Terms

a(0) =3a(1) =6a(2) =8a(3) =24a(4) =48a(5) =124a(6) =312a(7) =834a(8) =2184a(9) =5928a(10) =16104a(11) =44344a(12) =122640a(13) =341796a(14) =956576a(15) =2690844a(16) =7596480a(17) =21524412a(18) =61171656a(19) =174342192a(20) =498111952a(21) =1426419852a(22) =4093181688a(23) =11767919284a(24) =33891544368a(25) =97764131640a(26) =282429535752a(27) =817028472936