cp's OEIS Frontend

A360458 Two times the median of the set of distinct prime factors of n; a(1) = 2.

%I A360458 #6 Feb 15 2023 21:48:18
%S A360458 2,4,6,4,10,5,14,4,6,7,22,5,26,9,8,4,34,5,38,7,10,13,46,5,10,15,6,9,
%T A360458 58,6,62,4,14,19,12,5,74,21,16,7,82,6,86,13,8,25,94,5,14,7,20,15,106,
%U A360458 5,16,9,22,31,118,6,122,33,10,4,18,6,134,19,26,10,142,5
%N A360458 Two times the median of the set of distinct prime factors of n; a(1) = 2.
%C A360458 The median of a multiset is either the middle part (for odd length), or the average of the two middle parts (for even length). Since the denominator is always 1 or 2, the median can be represented as an integer by multiplying by 2.
%e A360458 The prime factors of 336 are {2,2,2,2,3,7}, with distinct parts {2,3,7}, with median 3, so a(336) = 6.
%t A360458 Table[2*Median[First/@FactorInteger[n]],{n,100}]
%Y A360458 The union is 2 followed by A014091, complement of A014092.
%Y A360458 Distinct prime factors are listed by A027748.
%Y A360458 The version for divisors is A063655.
%Y A360458 Positions of odd terms are A100367.
%Y A360458 For mean instead of two times median we have A323171/A323172.
%Y A360458 The version for prime indices is A360005.
%Y A360458 The version for distinct prime indices is A360457.
%Y A360458 The version for prime factors is A360459.
%Y A360458 The version for prime multiplicities is A360460.
%Y A360458 Positions of even terms are A360552.
%Y A360458 The version for 0-prepended differences is A360555.
%Y A360458 A112798 lists prime indices, length A001222, sum A056239.
%Y A360458 A304038 lists distinct prime indices.
%Y A360458 A359893 and A359901 count partitions by median, odd-length A359902.
%Y A360458 Cf. A000975, A026424, A078174, A316413, A325347, A359907, A360006, A360248, A360453, A360550, A360551.
%K A360458 nonn
%O A360458 1,1
%A A360458 _Gus Wiseman_, Feb 14 2023