a(n) is the concatenation of its nontrivial divisors.

Terms

a(0) =0a(1) =0a(2) =0a(3) =2a(4) =0a(5) =23a(6) =0a(7) =24a(8) =3a(9) =25a(10) =0a(11) =2346a(12) =0a(13) =27a(14) =35a(15) =248a(16) =0a(17) =2369a(18) =0a(19) =24510a(20) =37a(21) =211a(22) =0a(23) =2346812a(24) =5a(25) =213a(26) =39a(27) =24714a(28) =0a(29) =23561015