a(n) = A047980(2n).

Terms

a(0) =3a(1) =7a(2) =17a(3) =71a(4) =19a(5) =59a(6) =167a(7) =757a(8) =197a(9) =159a(10) =799a(11) =227a(12) =317a(13) =415a(14) =361a(15) =521a(16) =3289a(17) =2633a(18) =1637a(19) =1861a(20) =1691a(21) =1997a(22) =2053a(23) =4097a(24) =6437a(25) =5731a(26) =9199a(27) =11603a(28) =5641a(29) =3833