This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A347939 #9 Sep 20 2021 21:29:01 %S A347939 155925,225225,259875,294525,297675,363825,405405,429975,496125, %T A347939 552825,562275,571725,606375,628425,694575,760725,765765,921375, %U A347939 945945,987525,1044225,1167075,1195425,1334025,1412775,1447875,1486485,1507275,1526175,1611225,1640925,1645875 %N A347939 Primitive terms of A347936: terms of A347936 that are not multiples of other terms of A347936. %C A347939 Since any positive odd multiple of a term of A347936 is also a term of A347936, the sequence A347936 consists of the positive odd multiple of this sequence. %H A347939 Amiram Eldar, <a href="/A347939/b347939.txt">Table of n, a(n) for n = 1..10000</a> %e A347939 The first 8 terms of this sequence are the same as those of A347936. But A347936(9) = 467775 = 3 * 155925 = 3 * A347936(1) is not a term of this sequence. %t A347939 abQ[n_] := DivisorSigma[1, n] > 2*n; s[n_] := DivisorSum[n, # &, abQ[#] &]; q[n_] := s[n] > 2*n && AllTrue[Most @ Divisors[n], ! q[#] &]; Select[Range[1, 300000, 2], q] %Y A347939 Subsequence A005101, A005231, A347936 and A347938. %Y A347939 Cf. A006038, A187795. %K A347939 nonn %O A347939 1,1 %A A347939 _Amiram Eldar_, Sep 20 2021