If n = 2^a * 3^b * 5^c * 7^d * ... then a(n) = a + 10 * b + 100 * c + 1000 * d + ... .

Terms

a(0) =0a(1) =1a(2) =10a(3) =2a(4) =100a(5) =11a(6) =1000a(7) =3a(8) =20a(9) =101a(10) =10000a(11) =12a(12) =100000a(13) =1001a(14) =110a(15) =4a(16) =1000000a(17) =21a(18) =10000000a(19) =102a(20) =1010a(21) =10001a(22) =100000000a(23) =13a(24) =200a(25) =100001a(26) =30a(27) =1002a(28) =1000000000a(29) =111