|
%I #14 Nov 07 2020 11:36:42
%S 2,105,165,195,3003,3927,4389,4641,4845,5187,5313,5865,6555,7395,7905,
%T 8265,8835,9435,10005,10455,10545,10695,10965,11685,11985,12255,12765,
%U 13395,13485,13515,14145,14835,15045,15105,15555,16215,16815,17085
%N Primitive elements of A119432.
%C Elements of A119432 that are not divisible by any smaller element of that sequence.
%C Appears to be the lexicographically latest sequence of squarefree numbers such that all numbers with abundance >= -1 (see A103288) are divisible by one of the terms. - _Peter Munn_, Oct 19 2020
%H Charles R Greathouse IV, <a href="/A119433/b119433.txt">Table of n, a(n) for n = 1..10000</a>
%F 2 followed by odd elements of A119431.
%e From _Peter Munn_, Oct 23 2020: (Start)
%e Initial terms, showing factorization:
%e n a(n)
%e 1 2 = 2
%e 2 105 = 3 * 5 * 7
%e 3 165 = 3 * 5 * 11
%e 4 195 = 3 * 5 * 13
%e 5 3003 = 3 * 7 * 11 * 13
%e 6 3927 = 3 * 7 * 11 * 17
%e 7 4389 = 3 * 7 * 11 * 19
%e 8 4641 = 3 * 7 * 13 * 17
%e 9 4845 = 3 * 5 * 17 * 19
%e 10 5187 = 3 * 7 * 13 * 19
%e 11 5313 = 3 * 7 * 11 * 23
%e 12 5865 = 3 * 5 * 17 * 23
%e 13 6555 = 3 * 5 * 19 * 23
%e 14 7395 = 3 * 5 * 17 * 29
%e 15 7905 = 3 * 5 * 17 * 31
%e (End)
%t Block[{a = {}}, Do[If[And[NoneTrue[a, Mod[i, #] == 0 &], 2 EulerPhi[i] <= i], AppendTo[a, i]], {i, 20000}]; a] (* _Michael De Vlieger_, Nov 05 2020 *)
%Y Subsequence of A005117, A119432.
%Y Cf. A103288.
%K nonn
%O 1,1
%A _Franklin T. Adams-Watters_, May 19 2006
| 