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 A064040 #33 Apr 18 2024 21:46:24
%S A064040 6,10,12,14,15,18,20,21,22,24,26,28,30,33,34,35,36,38,39,40,42,44,45,
%T A064040 46,48,50,51,52,54,55,56,57,58,60,62,63,65,66,68,69,70,72,74,75,76,77,
%U A064040 78,80,82,84,85,86,87,88,90,91,92,93,94,95,96,98,99,100,102,104,105
%N A064040 Integers whose number of distinct prime divisors is prime.
%C A064040 For all terms below 210 this sequence and A024619 are identical.
%H A064040 Harry J. Smith, <a href="/A064040/b064040.txt">Table of n, a(n) for n = 1..1000</a>
%e A064040 210 = 2*3*5*7 has 4 prime factors, hence it is not here, but it is part of A024619.
%p A064040 q:= n-> isprime(nops(ifactors(n)[2])):
%p A064040 select(q, [$1..210])[]; # _Alois P. Heinz_, Apr 18 2024
%t A064040 Select[Range[200], PrimeQ[PrimeNu[#]] &] (* _Paolo Xausa_, Mar 28 2024 *)
%o A064040 (PARI) n=0; for (m=1, 10^9, if (isprime(omega(m)), write("b064040.txt", n++, " ", m); if (n==1000, break))) \\ _Harry J. Smith_, Sep 06 2009
%o A064040 (PARI) is(n)=isprime(omega(n)) \\ _Charles R Greathouse IV_, Sep 18 2015
%Y A064040 Cf. A001221, A024619, A000977, A033992, A007774, A033993, A051270, A063989.
%K A064040 nonn,easy
%O A064040 1,1
%A A064040 _Lior Manor_, Aug 23 2001
%E A064040 Edited by _Charles R Greathouse IV_, Mar 18 2010
%E A064040 Name edited by _Michel Marcus_, Oct 16 2023