OFFSET
1,1
EXAMPLE
The positive integers with an exponent 6 in their prime-factorizations are 64 = 2^6, 192 = 2^6 *3^1, 320 = 2^6 *5^1, 448 = 2^6 *7^1, 576 = 2^6 *3^2, 704 = 2^6 *11^1, 729 = 3^6,...etc. The 6th of these is 704, so a(6) = 704.
MATHEMATICA
f[n_] := Min[3^n, 2^n*(2n - 1)]; Table[f[n], {n, 30}] (* Ray Chandler, Nov 23 2006 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Leroy Quet, Nov 19 2006
EXTENSIONS
Extended by Ray Chandler, Nov 23 2006
STATUS
approved