A transform of the Jacobsthal numbers.

Terms

a(0) =0a(1) =1a(2) =1a(3) =3a(4) =3a(5) =8a(6) =9a(7) =21a(8) =25a(9) =54a(10) =68a(11) =139a(12) =183a(13) =358a(14) =489a(15) =924a(16) =1301a(17) =2390a(18) =3450a(19) =6194a(20) =9126a(21) =16080a(22) =24093a(23) =41805a(24) =63507a(25) =108817a(26) =167188a(27) =283533a(28) =439689a(29) =739391