cp's OEIS Frontend

A324697 Lexicographically earliest sequence of positive integers > 1 that are prime or whose prime indices already belong to the sequence.

%I A324697 #5 Mar 11 2019 09:37:04
%S A324697 2,3,5,7,9,11,13,15,17,19,23,25,27,29,31,33,37,41,43,45,47,51,53,55,
%T A324697 59,61,67,69,71,73,75,79,81,83,85,89,93,97,99,101,103,107,109,113,115,
%U A324697 121,123,125,127,131,135,137,139,141,149,151,153,155,157,163,165
%N A324697 Lexicographically earliest sequence of positive integers > 1 that are prime or whose prime indices already belong to the sequence.
%C A324697 A self-describing sequence, similar to A304360.
%C A324697 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.
%e A324697 The sequence of terms together with their prime indices begins:
%e A324697    2: {1}
%e A324697    3: {2}
%e A324697    5: {3}
%e A324697    7: {4}
%e A324697    9: {2,2}
%e A324697   11: {5}
%e A324697   13: {6}
%e A324697   15: {2,3}
%e A324697   17: {7}
%e A324697   19: {8}
%e A324697   23: {9}
%e A324697   25: {3,3}
%e A324697   27: {2,2,2}
%e A324697   29: {10}
%e A324697   31: {11}
%e A324697   33: {2,5}
%e A324697   37: {12}
%e A324697   41: {13}
%e A324697   43: {14}
%e A324697   45: {2,2,3}
%t A324697 aQ[n_]:=Switch[n,1,False,_?PrimeQ,True,_,And@@Cases[FactorInteger[n],{p_,k_}:>aQ[PrimePi[p]]]];
%t A324697 Select[Range[100],aQ]
%Y A324697 Complement of A324705.
%Y A324697 Cf. A000002, A000720, A001222, A001462, A007097, A055396, A061395, A079000, A079254, A109298, A112798, A276625, A277098, A304360.
%Y A324697 Cf. A324694, A324695, A324696, A324698, A324699, A324700, A324701, A324702, A324703, A324704.
%K A324697 nonn
%O A324697 1,1
%A A324697 _Gus Wiseman_, Mar 10 2019