A019268 - cp's OEIS frontend

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.

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

[1, 5, 13, 37, 73, 673, 1993, 15013, 49681, 239233, 1065601, 8524807, 68198461, 545587687, 1704961513, 7811750017]