Duplicate of A023870.

Terms

a(0) =2a(1) =3a(2) =11a(3) =17a(4) =40a(5) =56a(6) =104a(7) =136a(8) =219a(9) =265a(10) =397a(11) =475a(12) =672a(13) =776a(14) =1046a(15) =1198a(16) =1561a(17) =1755a(18) =2223