OFFSET
1,3
EXAMPLE
The a(80) = 7 factorizations:
(2*2*2*10)
(2*2*20)
(2*5*8)
(2*40)
(4*20)
(8*10)
(80)
MATHEMATICA
facs[n_]:=If[n<=1, {{}}, Join@@Table[Map[Prepend[#, d]&, Select[facs[n/d], Min@@#>=d&]], {d, Rest[Divisors[n]]}]];
Table[Length[Select[facs[n], IntegerQ[Mean[#]]&]], {n, 2, 100}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Gus Wiseman, Jul 14 2019
STATUS
approved