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A324695 Lexicographically earliest sequence of positive integers whose prime indices are not already in the sequence. 54
1, 3, 7, 9, 11, 13, 19, 21, 27, 29, 33, 37, 39, 43, 47, 49, 53, 57, 59, 61, 63, 71, 77, 79, 81, 83, 87, 89, 91, 97, 99, 101, 107, 111, 113, 117, 121, 127, 129, 131, 133, 139, 141, 143, 147, 149, 151, 159, 163, 169, 171, 173, 177, 179, 181, 183, 189, 193, 197 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
A self-describing sequence, similar to A304360.
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.
LINKS
EXAMPLE
The sequence of terms together with their prime indices begins:
1: {}
3: {2}
7: {4}
9: {2,2}
11: {5}
13: {6}
19: {8}
21: {2,4}
27: {2,2,2}
29: {10}
33: {2,5}
37: {12}
39: {2,6}
43: {14}
47: {15}
49: {4,4}
53: {16}
57: {2,8}
59: {17}
61: {18}
63: {2,2,4}
MATHEMATICA
aQ[n_]:=And@@Cases[If[n==1, {}, FactorInteger[n]], {p_, k_}:>!aQ[PrimePi[p]]];
Select[Range[100], aQ]
CROSSREFS
Complement of A324694. Prime indices are A304360.
Sequence in context: A104381 A136333 A134454 * A113522 A222262 A027897
KEYWORD
nonn
AUTHOR
Gus Wiseman, Mar 10 2019
STATUS
approved

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Last modified March 28 13:42 EDT 2024. Contains 371254 sequences. (Running on oeis4.)