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A298864 Ranks of products 3*p when all primes p and products 3*p are jointly ranked. 2
4, 6, 9, 12, 16, 18, 22, 24, 28, 33, 35, 41, 43, 45, 49, 53, 57, 60, 65, 67, 68, 73, 76, 80, 86, 88, 90, 94, 95, 98, 106, 109, 113, 114, 121, 123, 128, 131, 134, 137, 140, 142, 148, 150, 152, 154, 162, 169, 172, 174, 176, 179, 181, 187, 191, 194, 196, 199 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Clark Kimberling, Table of n, a(n) for n = 1..1000

EXAMPLE

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,...

MATHEMATICA

z = 1000; u = Prime[Range[z]]; w = Take[Union[u, 3 u], z];

p[n_] := If[MemberQ[u, w[[n]]], 0, 1];

Take[w, z];  (* A105585 *)

t = Table[p[n], {n, 1, z}];

Flatten[Position[t, 0]];  (* A298863 *)

Flatten[Position[t, 1]];  (* A298864 *)

CROSSREFS

Cf. A000040, A105585, A298863 (complement).

Sequence in context: A163656 A100915 A144922 * A310667 A317538 A310668

Adjacent sequences:  A298861 A298862 A298863 * A298865 A298866 A298867

KEYWORD

nonn,easy

AUTHOR

Clark Kimberling, Feb 13 2018

STATUS

approved

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Last modified October 28 04:43 EDT 2021. Contains 348313 sequences. (Running on oeis4.)