OFFSET
1,2
COMMENTS
EXAMPLE
The terms together with their corresponding rooted trees begin:
1: o
4: (oo)
8: (ooo)
16: (oooo)
27: ((o)(o)(o))
54: (o(o)(o)(o))
81: ((o)(o)(o)(o))
162: (o(o)(o)(o)(o))
243: ((o)(o)(o)(o)(o))
486: (o(o)(o)(o)(o)(o))
729: ((o)(o)(o)(o)(o)(o))
MATHEMATICA
MGTree[n_]:=If[n==1, {}, MGTree/@Flatten[Cases[FactorInteger[n], {p_, k_}:>Table[PrimePi[p], {k}]]]];
rd=Table[Count[MGTree[n], _, {0, Infinity}]-(Depth[MGTree[n]]-1), {n, 10000}];
Table[Position[rd, k][[1, 1]], {k, Union[rd]}]
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Gus Wiseman, Dec 01 2022
STATUS
approved