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%I #10 Nov 06 2018 13:16:31
%S 4,6,9,12,16,18,22,24,28,33,35,41,43,45,49,53,57,60,65,67,68,73,76,80,
%T 86,88,90,94,95,98,106,109,113,114,121,123,128,131,134,137,140,142,
%U 148,150,152,154,162,169,172,174,176,179,181,187,191,194,196,199
%N Ranks of products 3*p when all primes p and products 3*p are jointly ranked.
%H Clark Kimberling, <a href="/A298864/b298864.txt">Table of n, a(n) for n = 1..1000</a>
%e A105585 = ordered sequence of primes p and products 3*p: 2, 3, 5, 6, 7, 9, 11, 13, 15, 17, ... in which primes occupy ranks 4,6,9,11,...
%t z = 1000; u = Prime[Range[z]]; w = Take[Union[u, 3 u], z];
%t p[n_] := If[MemberQ[u, w[[n]]], 0, 1];
%t Take[w, z]; (* A105585 *)
%t t = Table[p[n], {n, 1, z}];
%t Flatten[Position[t, 0]]; (* A298863 *)
%t Flatten[Position[t, 1]]; (* A298864 *)
%Y Cf. A000040, A105585, A298863 (complement).
%K nonn,easy
%O 1,1
%A _Clark Kimberling_, Feb 13 2018
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