cp's OEIS Frontend

A298540 Matula-Goebel numbers of rooted trees such that every branch of the root has a different number of nodes.

%I A298540 #5 Jan 22 2018 03:08:06
%S A298540 1,2,3,5,6,7,10,11,13,14,15,17,19,21,22,23,26,29,30,31,33,34,37,38,39,
%T A298540 41,42,43,46,47,51,53,55,57,58,59,61,62,65,66,67,69,71,73,74,77,78,79,
%U A298540 82,83,85,86,87,89,91,93,94,95,97,101,102,103,106,107,109
%N A298540 Matula-Goebel numbers of rooted trees such that every branch of the root has a different number of nodes.
%e A298540 Sequence of trees begins:
%e A298540 1  o
%e A298540 2  (o)
%e A298540 3  ((o))
%e A298540 5  (((o)))
%e A298540 6  (o(o))
%e A298540 7  ((oo))
%e A298540 10 (o((o)))
%e A298540 11 ((((o))))
%e A298540 13 ((o(o)))
%e A298540 14 (o(oo))
%e A298540 15 ((o)((o)))
%e A298540 17 (((oo)))
%e A298540 19 ((ooo))
%e A298540 21 ((o)(oo))
%e A298540 22 (o(((o))))
%e A298540 23 (((o)(o)))
%e A298540 26 (o(o(o)))
%e A298540 29 ((o((o))))
%e A298540 30 (o(o)((o)))
%t A298540 nn=500;
%t A298540 primeMS[n_]:=If[n===1,{},Flatten[Cases[FactorInteger[n],{p_,k_}:>Table[PrimePi[p],{k}]]]];
%t A298540 MGweight[n_]:=If[n===1,1,1+Total[MGweight/@primeMS[n]]];
%t A298540 Select[Range[nn],UnsameQ@@MGweight/@primeMS[#]&]
%Y A298540 Cf. A000081, A007097, A061775, A111299, A214577, A276625, A290760, A291442, A297571, A298479, A298534, A298536, A298538, A298539.
%K A298540 nonn
%O A298540 1,2
%A A298540 _Gus Wiseman_, Jan 21 2018