%I #17 Sep 08 2022 08:45:05
%S 2,4,12,15,16,18,22,28,34,35,38,39,44,45,46,48,50,51,52,58,62,65,68,
%T 69,76,80,82,85,86,88,92,95,96,100,104,105,106,108,118,132,136,138,
%U 141,144,145,152,158,159,164,166,171,174,175,178,188,194,196,201,202,205
%N Numbers k such that k and k^2+1 have the same number of distinct prime factors.
%H Amiram Eldar, <a href="/A067268/b067268.txt">Table of n, a(n) for n = 1..10000</a>
%F Numbers k such that omega(k) = omega(k^2+1).
%e 2 is a term since omega(2) = omega(2^2+1) = 1.
%t Select[Range[250],PrimeNu[#]==PrimeNu[#^2+1]&] (* _Harvey P. Dale_, Feb 07 2019 *)
%o (Magma) [k:k in [1.. 210 ]| #PrimeDivisors(k) eq #PrimeDivisors(k^2+1)]; // _Marius A. Burtea_, Feb 18 2020
%Y Cf. A001221, A002522, A128428, A272044.
%K easy,nonn
%O 1,1
%A _Benoit Cloitre_, Feb 21 2002