OFFSET
1,1
COMMENTS
Analogous to A053047 (the same with a similar large initial value, n!).
EXAMPLE
n=6, A002110(6)=30030; the corresponding iteration chain is {30030, 5760, 1536, 512, 256, 128, 64, 32, 16, 8, 4, 2, 1}. The first power of 2 is the 4th item after 3 iterations. It is 512, therefore a(6)=512.
MATHEMATICA
a[n_] := 2^ Max@ IntegerExponent[ FixedPointList[ EulerPhi, Times @@ Prime[Range[n]]], 2]; Array[a, 20] (* Giovanni Resta, May 30 2018 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Labos Elemer, Feb 28 2000
STATUS
approved