a(1) = 1, a(n) = concatenation of two closest factors of a(n-1) whose product equals a(n-1) or if a(n-1) is a prime then the concatenation of 1 and a(n-1).

A062095

a(1) = 1, a(n) = concatenation of two closest factors of a(n-1) whose product equals a(n-1) or if a(n-1) is a prime then the concatenation of 1 and a(n-1).

Terms

    a(0) =1a(1) =11a(2) =111a(3) =337a(4) =1337a(5) =7191a(6) =51141a(7) =317047a(8) =1317047a(9) =2814687a(10) =9312743a(11) =25193697a(12) =30981533a(13) =51496017a(14) =192326779a(15) =1427134777a(16) =4987286171a(17) =6471777063a(18) =61653104971a(19) =259323776747a(20) =737046253821

External references