Concatenated indices of primes in prime factorization of n.

Terms

a(0) =1a(1) =2a(2) =11a(3) =3a(4) =21a(5) =4a(6) =111a(7) =22a(8) =31a(9) =5a(10) =211a(11) =6a(12) =41a(13) =32a(14) =1111a(15) =7a(16) =221a(17) =8a(18) =311a(19) =42a(20) =51a(21) =9a(22) =2111a(23) =33a(24) =61a(25) =222a(26) =411a(27) =10a(28) =321a(29) =11