Concatenate exponents in prime factorization of n.

Terms

a(0) =0a(1) =1a(2) =1a(3) =2a(4) =1a(5) =11a(6) =1a(7) =3a(8) =2a(9) =11a(10) =1a(11) =21a(12) =1a(13) =11a(14) =11a(15) =4a(16) =1a(17) =12a(18) =1a(19) =21a(20) =11a(21) =11a(22) =1a(23) =31a(24) =2a(25) =11a(26) =3a(27) =21a(28) =1a(29) =111