(Terms in A028279)/2.

Terms

a(0) =2a(1) =3a(2) =5a(3) =3a(4) =8a(5) =8a(6) =4a(7) =16a(8) =4a(9) =5a(10) =20a(11) =43a(12) =55a(13) =43a(14) =20a(15) =5a(16) =25a(17) =63a(18) =98a(19) =98a(20) =63a(21) =25a(22) =6a(23) =88a(24) =161a(25) =196a(26) =161a(27) =88a(28) =6a(29) =249