cp's OEIS Frontend

A325700 Numbers with as many distinct even as distinct odd prime indices.

%I A325700 #5 May 17 2019 22:06:49
%S A325700 1,6,12,14,15,18,24,26,28,33,35,36,38,45,48,51,52,54,56,58,65,69,72,
%T A325700 74,75,76,77,86,93,95,96,98,99,104,106,108,112,116,119,122,123,135,
%U A325700 141,142,143,144,145,148,152,153,158,161,162,172,175,177,178,185,192
%N A325700 Numbers with as many distinct even as distinct odd prime indices.
%C A325700 These are the Heinz numbers of the integer partitions counted by A241638.
%C A325700 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.
%e A325700 The sequence of terms together with their prime indices begins:
%e A325700     1: {}
%e A325700     6: {1,2}
%e A325700    12: {1,1,2}
%e A325700    14: {1,4}
%e A325700    15: {2,3}
%e A325700    18: {1,2,2}
%e A325700    24: {1,1,1,2}
%e A325700    26: {1,6}
%e A325700    28: {1,1,4}
%e A325700    33: {2,5}
%e A325700    35: {3,4}
%e A325700    36: {1,1,2,2}
%e A325700    38: {1,8}
%e A325700    45: {2,2,3}
%e A325700    48: {1,1,1,1,2}
%e A325700    51: {2,7}
%e A325700    52: {1,1,6}
%e A325700    54: {1,2,2,2}
%e A325700    56: {1,1,1,4}
%e A325700    58: {1,10}
%t A325700 Select[Range[100],0==Total[(-1)^PrimePi/@First/@If[#==1,{},FactorInteger[#]]]&]
%Y A325700 A324967(n) = A324966(n).
%Y A325700 Cf. A001221, A026010, A028260, A045931, A063886, A097613, A112798, A130780, A239241, A241638, A325698, A325699.
%K A325700 nonn
%O A325700 1,2
%A A325700 _Gus Wiseman_, May 17 2019