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 A308967 #18 Feb 24 2020 08:17:42
%S A308967 0,1,1,2,1,2,3,1,1,3,2,3,3,2,2,3,2,3,2,2,1,5,2,3,2,1,3,3,3,5,2,3,2,2,
%T A308967 2,5,2,4,2,4,1,4,3,4,3,4,4,3,2,3,3,5,2,3,2,1,3,5,2,4,2,1,4,4,4,6,4,2,
%U A308967 1,4,4,4,3,3,4,4,5,4,1,4,3,3,4,4,3,3,4,5,1,2,1,3,2,2,3,3,3,3,3
%N A308967 Number of prime factors (with multiplicity) of the numerator A001008 of the harmonic number H(n) = Sum_{k=1..n} 1/k.
%H A308967 Amiram Eldar, <a href="/A308967/b308967.txt">Table of n, a(n) for n = 1..325</a>
%F A308967 a(n) = A001222(A001008(n)).
%e A308967 H(1) = 1 = 1/1, the numerator is the empty product, whence a(1) = 0.
%e A308967 H(2) = 1 + 1/2 = 3/2 and H(3) = 3/2 + 1/3 = 11/6, 3 and 11 are prime numbers, whence a(2) = a(3) = 1.
%e A308967 H(4) = 11/6 + 1/4 = 25/12, 25 = 5^2, whence a(4) = 2.
%t A308967 Table[PrimeOmega @ Numerator[HarmonicNumber[n]], {n, 30}] (* _Amiram Eldar_, Feb 24 2020 *)
%o A308967 (PARI) a(n)=bigomega(A001008(n))
%Y A308967 Cf. A001008, A001222.
%K A308967 nonn
%O A308967 1,4
%A A308967 _M. F. Hasler_, Jul 03 2019