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 A348097 #14 Sep 30 2021 17:32:37 %S A348097 1,12,18,20,24,28,40,44,45,48,50,52,54,56,63,68,75,76,80,88,92,96,98, %T A348097 99,104,112,116,117,124,135,136,147,148,152,153,160,162,164,171,172, %U A348097 175,176,184,188,189,192,207,208,212,224,232,236,242,244,245,248,250,261 %N A348097 Numbers having equally many unitary and nonunitary prime divisors. %C A348097 A prime divisor of k is unitary if its exponent in the prime factorization of k is 1, and is nonunitary otherwise. %C A348097 Numbers k such that A056169(k) = A056170(k) = A001221(k)/2. %C A348097 A345381 is a subsequence. After a(1) = 1, a(238) = 1260 is the next term that is not in A345381. %H A348097 Amiram Eldar, <a href="/A348097/b348097.txt">Table of n, a(n) for n = 1..10000</a> %e A348097 12 = 2^2 * 3 is a term since it has one unitary prime divisor (3) and one nonunitary prime divisor (2). %t A348097 q[n_] := n == 1 || Count[(e = FactorInteger[n][[;; , 2]]), 1] == Length[e]/2; Select[Range[300], q] %Y A348097 Cf. A001221, A056169, A056170, A345381. %Y A348097 Subsequence of A030231. %Y A348097 Similar sequences: A016825 (odd and even divisors), A048109, A187039. %K A348097 nonn %O A348097 1,2 %A A348097 _Amiram Eldar_, Sep 30 2021