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A073061
a(1)=1, a(2k)=2*a(k), a(2k+1)=3*a(k).
1
1, 2, 3, 4, 6, 6, 9, 8, 12, 12, 18, 12, 18, 18, 27, 16, 24, 24, 36, 24, 36, 36, 54, 24, 36, 36, 54, 36, 54, 54, 81, 32, 48, 48, 72, 48, 72, 72, 108, 48, 72, 72, 108, 72, 108, 108, 162, 48, 72, 72, 108, 72, 108, 108, 162, 72, 108, 108, 162, 108, 162, 162, 243, 64, 96, 96
OFFSET
1,2
COMMENTS
All terms are 3-smooth (see A003586). The number of appearances of 2^a * 3^b is binomial(a+b,a). - Ivan Neretin, Jun 05 2016
LINKS
FORMULA
There is no general formula but a(5+4k)=a(6+4k), a(A029744(k))=A029744(k), sum(k=1, n, a(k)) is asymptotic to C*n^2*Log(n) with C=0.23...
2^A023416(n) * 3^(A000120(n)-1), n>0. - Ralf Stephan, Mar 18 2004
MATHEMATICA
Fold[Join[#1, {2 #1[[#2]], 3 #1[[#2]]}] &, {1}, Range[33]] (* Ivan Neretin, Jun 05 2016 *)
CROSSREFS
Sequence in context: A157450 A195013 A079667 * A300526 A006874 A357476
KEYWORD
nonn
AUTHOR
Benoit Cloitre, Aug 16 2002
STATUS
approved