Let Dedekind's psi(m) = product of (p+1)p^(e-1) for primes p, where p^e is a factor of m. Iterating psi(m) eventually results in a number of form 2^a*3^b. a(n) is the smallest number that requires n steps to reach such a number.

A019268

Let Dedekind's psi(m) = product of (p+1)p^(e-1) for primes p, where p^e is a factor of m. Iterating psi(m) eventually results in a number of form 2^a*3^b. a(n) is the smallest number that requires n steps to reach such a number.

Terms

    a(0) =1a(1) =5a(2) =13a(3) =37a(4) =73a(5) =673a(6) =1993a(7) =15013a(8) =49681a(9) =239233a(10) =1065601a(11) =8524807a(12) =68198461a(13) =545587687a(14) =1704961513a(15) =7811750017

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