cp's OEIS Frontend

A324698 Lexicographically earliest sequence containing 2 and all numbers > 1 whose prime indices already belong to the sequence.

%I A324698 #5 Mar 11 2019 09:37:12
%S A324698 2,3,5,9,11,15,23,25,27,31,33,45,47,55,69,75,81,83,93,97,99,103,115,
%T A324698 121,125,127,135,137,141,155,165,197,207,211,225,235,243,249,253,257,
%U A324698 275,279,291,297,309,341,345,347,363,375,379,381,405,411,415,419,423
%N A324698 Lexicographically earliest sequence containing 2 and all numbers > 1 whose prime indices already belong to the sequence.
%C A324698 A self-describing sequence, similar to A304360.
%C A324698 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 A324698 The sequence of terms together with their prime indices begins:
%e A324698    2: {1}
%e A324698    3: {2}
%e A324698    5: {3}
%e A324698    9: {2,2}
%e A324698   11: {5}
%e A324698   15: {2,3}
%e A324698   23: {9}
%e A324698   25: {3,3}
%e A324698   27: {2,2,2}
%e A324698   31: {11}
%e A324698   33: {2,5}
%e A324698   45: {2,2,3}
%e A324698   47: {15}
%e A324698   55: {3,5}
%e A324698   69: {2,9}
%e A324698   75: {2,3,3}
%e A324698   81: {2,2,2,2}
%e A324698   83: {23}
%e A324698   93: {2,11}
%e A324698   97: {25}
%e A324698   99: {2,2,5}
%t A324698 aQ[n_]:=Switch[n,1,False,2,True,_,And@@Cases[FactorInteger[n],{p_,k_}:>aQ[PrimePi[p]]]];
%t A324698 Select[Range[100],aQ]
%Y A324698 Complement of A324704.
%Y A324698 Cf. A000002, A000720, A001222, A001462, A007097, A055396, A061395, A079000, A079254, A109298, A112798, A276625, A277098, A304360.
%Y A324698 Cf. A324694, A324695, A324696, A324697, A324699, A324700, A324701, A324702, A324703, A324705.
%K A324698 nonn
%O A324698 1,1
%A A324698 _Gus Wiseman_, Mar 10 2019