a(n) = A248101(A277324(n)).

Terms

a(0) =1a(1) =3a(2) =9a(3) =3a(4) =9a(5) =27a(6) =9a(7) =21a(8) =63a(9) =27a(10) =81a(11) =189a(12) =63a(13) =189a(14) =441a(15) =21a(16) =63a(17) =1323a(18) =567a(19) =1323a(20) =3969a(21) =1701a(22) =3969a(23) =1323a(24) =441a(25) =9261a(26) =27783a(27) =1323a(28) =3087a(29) =9261