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A304327
Number of ways to write n as a product of a perfect power and a squarefree number.
10
1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 2, 1, 2, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 2, 1
OFFSET
1,8
COMMENTS
First term greater than 2 is a(746496) = 3.
LINKS
EXAMPLE
The a(746496) = 3 ways are 12^5*3, 72^3*2, 864^2*1.
MATHEMATICA
Table[Length[Select[Divisors[n], (#===1||GCD@@FactorInteger[#][[All, 2]]>1)&&SquareFreeQ[n/#]&]], {n, 100}]
PROG
(PARI) A304327(n) = sumdiv(n, d, issquarefree(n/d)*((1==d)||ispower(d))); \\ Antti Karttunen, Jul 29 2018
KEYWORD
nonn
AUTHOR
Gus Wiseman, May 10 2018
EXTENSIONS
More terms from Antti Karttunen, Jul 29 2018
STATUS
approved