Replace n with concatenation of its odd divisors.

Terms

a(0) =1a(1) =1a(2) =13a(3) =1a(4) =15a(5) =13a(6) =17a(7) =1a(8) =139a(9) =15a(10) =111a(11) =13a(12) =113a(13) =17a(14) =13515a(15) =1a(16) =117a(17) =139a(18) =119a(19) =15a(20) =13721a(21) =111a(22) =123a(23) =13a(24) =1525a(25) =113a(26) =13927a(27) =17a(28) =129a(29) =13515