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 A098903 #11 Feb 15 2025 17:05:42
%S A098903 3,5,7,9,11,13,17,19,23,25,27,29,31,37,41,43,47,49,53,59,61,67,71,73,
%T A098903 79,81,83,89,97,101,103,105,107,109,113,121,125,127,131,137,139,149,
%U A098903 151,157,163,165,167,169,173,179,181,191,193,195,197,199,211,223,227,229
%N A098903 Odd numbers whose number of distinct prime factors is also odd.
%C A098903 This will also contain all odd primes.
%H A098903 Vincenzo Librandi, <a href="/A098903/b098903.txt">Table of n, a(n) for n = 1..1000</a>
%e A098903 25 is a member of sequence because 25 is odd and number of distinct prime factors of 25 i.e. 1 is also odd.
%t A098903 Select[Range[300],And@@OddQ[{#,PrimeNu[#]}]&] (* _Harvey P. Dale_, Feb 19 2014 *)
%t A098903 Select[Range[1,301,2],OddQ[PrimeNu[#]]&] (* _Harvey P. Dale_, Feb 15 2025 *)
%Y A098903 Cf. A001221.
%K A098903 nonn,easy
%O A098903 1,1
%A A098903 _Shyam Sunder Gupta_, Oct 14 2004