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A298863
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Ranks of primes p when all primes p and products 3*p are jointly ranked.
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2
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1, 2, 3, 5, 7, 8, 10, 11, 13, 14, 15, 17, 19, 20, 21, 23, 25, 26, 27, 29, 30, 31, 32, 34, 36, 37, 38, 39, 40, 42, 44, 46, 47, 48, 50, 51, 52, 54, 55, 56, 58, 59, 61, 62, 63, 64, 66, 69, 70, 71, 72, 74, 75, 77, 78, 79, 81, 82, 83, 84, 85, 87, 89, 91, 92, 93
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OFFSET
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1,2
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LINKS
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EXAMPLE
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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 1,2,3,5,7,8,10,...
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MATHEMATICA
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z = 1000; u = Prime[Range[z]]; w = Take[Union[u, 3 u], z];
p[n_] := If[MemberQ[u, w[[n]]], 0, 1];
t = Table[p[n], {n, 1, z}];
Flatten[Position[t, 0]]; (* A298863 *)
Flatten[Position[t, 1]]; (* A298864 *)
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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STATUS
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approved
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