a(n) is the smallest squarefree semiprime that belongs to a sequence of length n under repeated iteration of the map (k -> concatenation of prime divisors of k in increasing order) until a number is reached that is not a squarefree semiprime.

A243843

a(n) is the smallest squarefree semiprime that belongs to a sequence of length n under repeated iteration of the map (k -> concatenation of prime divisors of k in increasing order) until a number is reached that is not a squarefree semiprime.

Terms

    a(0) =6a(1) =38a(2) =34a(3) =15a(4) =265a(5) =161a(6) =1126a(7) =4891a(8) =1253a(9) =250231a(10) =100462a(11) =49869178a(12) =234139657a(13) =68279314a(14) =2318271253a(15) =636542506

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