cp's OEIS Frontend

A330098 Number of distinct multisets of multisets that can be obtained by permuting the vertices of the multiset of multisets with MM-number n.

%I A330098 #5 Dec 10 2019 12:15:35
%S A330098 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
%T A330098 2,1,2,1,2,1,1,1,1,1,2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,2,1,1,1,2,1,1,1,
%U A330098 2,2,2,1,1,2,2,1,2,2,1,1,1,1,1,1,1,1,2
%N A330098 Number of distinct multisets of multisets that can be obtained by permuting the vertices of the multiset of multisets with MM-number n.
%C A330098 A prime index of n is a number m such that prime(m) divides n. The multiset of prime indices of n is row n of A112798. The multiset of multisets with MM-number n is formed by taking the multiset of prime indices of each part of the multiset of prime indices of n. For example, the prime indices of 78 are {1,2,6}, so the multiset of multisets with MM-number 78 is {{},{1},{1,2}}.
%C A330098 a(n) is a divisor of A303975(n)!.
%e A330098 The vertex-permutations of {{1,2},{2,3,3}} are:
%e A330098   {{1,2},{1,3,3}}
%e A330098   {{1,2},{2,3,3}}
%e A330098   {{1,3},{1,2,2}}
%e A330098   {{1,3},{2,2,3}}
%e A330098   {{2,3},{1,1,2}}
%e A330098   {{2,3},{1,1,3}}
%e A330098 so a(4927) = 6.
%t A330098 primeMS[n_]:=If[n==1,{},Flatten[Cases[FactorInteger[n],{p_,k_}:>Table[PrimePi[p],{k}]]]];
%t A330098 graprms[m_]:=Union[Table[Sort[Sort/@(m/.Rule@@@Table[{p[[i]],i},{i,Length[p]}])],{p,Permutations[Union@@m]}]];
%t A330098 Table[Length[graprms[primeMS/@primeMS[n]]],{n,100}]
%Y A330098 Positions of 1's are A330232.
%Y A330098 Positions of first appearances are A330230 and A330233.
%Y A330098 The BII-number version is A330231.
%Y A330098 Cf. A001055, A003238, A007716, A055621, A056239, A112798, A302242, A303975, A322847, A330194, A330218, A330223, A330227, A330236.
%K A330098 nonn
%O A330098 1,35
%A A330098 _Gus Wiseman_, Dec 09 2019