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 A046470 #12 Apr 03 2025 01:43:17 %S A046470 2,8,12,18,20,28,30,32,42,44,48,50,52,66,68,70,72,76,78,80,92,98,102, %T A046470 108,110,112,114,116,120,124,128,130,138,148,154,162,164,168,170,172, %U A046470 174,176,180,182,186,188,190,192,200,208,212,222,230,236,238,242,244 %N A046470 Even numbers with an odd number of prime factors (counted with multiplicity). %H A046470 Robert Israel, <a href="/A046470/b046470.txt">Table of n, a(n) for n = 1..10000</a> %e A046470 a(2)=8, which is even with odd number of prime factors i.e. 3. %p A046470 filter:= proc(n) numtheory:-bigomega(n) mod 2 = 1 end proc: %p A046470 select(filter, [seq(i,i=2..1000,2)]); # _Robert Israel_, Apr 02 2025 %t A046470 Select[Range[2, 244, 2], OddQ[PrimeOmega[#]] &] (* _Jayanta Basu_, Jun 26 2013 *) %Y A046470 Cf. A046337. Intersection of A005843 and A026424. %K A046470 nonn %O A046470 1,1 %A A046470 _Shyam Sunder Gupta_, Feb 16 2002