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A019269 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 number of steps to reach such a number. 0
0, 0, 0, 0, 1, 0, 1, 0, 0, 1, 1, 0, 2, 1, 1, 0, 1, 0, 2, 1, 1, 1, 1, 0, 2, 2, 0, 1, 2, 1, 1, 0, 1, 1, 1, 0, 3, 2, 2, 1, 2, 1, 2, 1, 1, 1, 1, 0, 2, 2, 1, 2, 1, 0, 1, 1, 2, 2, 2, 1, 2, 1, 1, 0, 2, 1, 2, 1, 1, 1, 1, 0, 4, 3, 2, 2, 1, 2, 2, 1, 0, 2, 2, 1, 1, 2, 2, 1, 2, 1, 2, 1, 1, 1, 2, 0, 3, 2, 1 (list; graph; refs; listen; history; internal format)
OFFSET

1,13

REFERENCES

R. K. Guy, "Unsolved Problems in Number Theory", section B41.

Peter Giblin, "Primes and Programming - an Introduction to Number Theory with Computation", page 118.

CROSSREFS

Sequence in context: A078659 A079690 A040076 * A204459 A035155 A090584

Adjacent sequences:  A019266 A019267 A019268 * A019270 A019271 A019272

KEYWORD

nonn

AUTHOR

JudMcCranie(AT)ugaalum.uga.edu (JUD MCCRANIE)

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Last modified February 17 02:08 EST 2012. Contains 205978 sequences.