Replace 2n+1 with concatenation of its nontrivial divisors.

Terms

a(0) =0a(1) =0a(2) =0a(3) =0a(4) =3a(5) =0a(6) =0a(7) =35a(8) =0a(9) =0a(10) =37a(11) =0a(12) =5a(13) =39a(14) =0a(15) =0a(16) =311a(17) =57a(18) =0a(19) =313a(20) =0a(21) =0a(22) =35915a(23) =0a(24) =7a(25) =317a(26) =0a(27) =511a(28) =319a(29) =0