If a(n) is prime, a(n+1) = a(n) followed by a 1; if a(n) is composite, a(n+1) = concatenation of prime factors of a(n) (with multiplicity).

A049121

If a(n) is prime, a(n+1) = a(n) followed by a 1; if a(n) is composite, a(n+1) = concatenation of prime factors of a(n) (with multiplicity).

Terms

    a(0) =0a(1) =1a(2) =11a(3) =111a(4) =337a(5) =3371a(6) =33711a(7) =317661a(8) =3195573a(9) =33134361a(10) =313849599a(11) =3714945219a(12) =33412771691

External references