Thanks to everyone who made a donation during our annual appeal!
To see the list of donors, or make a donation, see the
OEIS Foundation home page.
Table of n, a(n) for n=1..25.
27=3^3 and 72=2^3*3^2 is powerful.
Cf. A001694, A115693.
Sequence in context: A029786 A029792 A112993 * A028935 A030089 A007235
Adjacent sequences: A115691 A115692 A115693 * A115695 A115696 A115697
Giovanni Resta, Jan 31 2006