%I A121615
%S A121615 2,3,5,7,11,13,15,17,19,23,29,31,35,37,41,43,47,49,53,59,61,67,71,73,79,
%T A121615 83,89,97,101,103,107,109,113,121,127,131,137,139,143,149,151,157,163,
%U A121615 167,169,173,179,181,187,191,193,197,199,211,221,223,227,229,233,239
%N A121615 Lexicographically smallest sequence such that the k-th prime occurs altogether 
               not more than k times as prime factor.
%C A121615 Subsequence of A037143: 1 <= A001222(a(n)) <= 2; A000040 is a subsequence.
%H A121615 R. Zumkeller, <a href="b121615.txt">Table of n, a(n) for n = 1..1000</
               a>
%e A121615 k=1, prime(1)=2: {2} = {a(1)},
%e A121615 k=2, prime(2)=3: {3,3*5} = {a(2),a(7)},
%e A121615 k=3, prime(3)=5: {5,3*5,5*7} = {a(3),a(7),a(13)},
%e A121615 k=4, prime(4)=7: {7,5*7,7*7} = {a(4),a(7),a(18)},
%e A121615 k=5, prime(5)=11: {11,11*11,11*13,11*17} = {a(5),a(34),a(39),a(49)},
%e A121615 k=6, prime(6)=13: {13,11*13,13*13,13*17,13*19} = {a(6),a(39),a(45),a(55),
               a(62)};
%e A121615 k=7, prime(7)=17: {17,11*17,13*17,17*17,17*19,17*23} = {a(8),a(49),a(55),
               a(71),a(77),a(90)}.
%Y A121615 Sequence in context: A069161 A003277 A117287 this_sequence A097605 A143578 
               A086070
%Y A121615 Adjacent sequences: A121612 A121613 A121614 this_sequence A121616 A121617 
               A121618
%K A121615 nonn
%O A121615 1,1
%A A121615 Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Aug 11 2006