cp's OEIS Frontend

A327517 Number of factorizations of n that are empty or have at least two factors, all of which are > 1 and pairwise coprime.

%I A327517 #4 Sep 20 2019 08:58:10
%S A327517 1,0,0,0,0,1,0,0,0,1,0,1,0,1,1,0,0,1,0,1,1,1,0,1,0,1,0,1,0,4,0,0,1,1,
%T A327517 1,1,0,1,1,1,0,4,0,1,1,1,0,1,0,1,1,1,0,1,1,1,1,1,0,4,0,1,1,0,1,4,0,1,
%U A327517 1,4,0,1,0,1,1,1,1,4,0,1,0,1,0,4,1,1,1
%N A327517 Number of factorizations of n that are empty or have at least two factors, all of which are > 1 and pairwise coprime.
%H A327517 Gus Wiseman, <a href="https://docs.google.com/document/d/e/2PACX-1vSX9dPMGJhxB8rOknCGvOs6PiyhupdWNpqLsnphdgU6MEVqFBnWugAXidDhwHeKqZe_YnUqYeGOXsOk/pub">Sequences counting and encoding certain classes of multisets</a>
%F A327517 a(n > 1) = A259936(n) - 1 = A000110(A001221(n)) - 1.
%t A327517 facs[n_]:=If[n<=1,{{}},Join@@Table[Map[Prepend[#,d]&,Select[facs[n/d],Min@@#>=d&]],{d,Rest[Divisors[n]]}]];
%t A327517 Table[Length[Select[facs[n],#=={}||CoprimeQ@@#&]],{n,100}]
%Y A327517 See link for additional cross-references.
%Y A327517 Cf. A302569, A302696, A304711, A305079, A327076, A327392.
%K A327517 nonn
%O A327517 1,30
%A A327517 _Gus Wiseman_, Sep 19 2019