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 A227067 #11 Aug 13 2013 17:50:50
%S A227067 3,51,32151,300863849741
%N A227067 Least n-prime p such that the number of even n-primes (<= p) equals the number of odd n-primes (<= p).
%C A227067 An n-prime is a number having n prime factors (counted multiply). For any n, the ratio of even n-primes to odd n-primes tends to decrease with the magnitude of the numbers. This may explain why the initial terms in A226835 are all even. The a(4) term is greater than 10^9.
%C A227067 There is only one other semiprime such that half of the previous semiprimes are odd: 62. For 3-primes, there are three other numbers: 32158, 32163, and 32170.
%e A227067 The first such prime is 3 because up to 3 there are an equal number of even and odd primes. The first such semiprime is 51 because there are 9 evens and 9 odds: 4, 6, 10, 14, 22, 26, 34, 38, 46 and 9, 15, 21, 25, 33, 35, 39, 49, 51.
%t A227067 nn = 3; Table[p = 1; odds = 0; evens = 0; While[odds*evens == 0 || odds != evens, p++; If[PrimeOmega[p] == n, If[OddQ[p], odds++, evens++]]]; p, {n, nn}]
%Y A227067 Cf. A226833, A226835, A227069.
%K A227067 nonn,hard,more
%O A227067 1,1
%A A227067 _T. D. Noe_, Jul 03 2013
%E A227067 a(4) from _Donovan Johnson_, Aug 13 2013