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 A093320 #11 Mar 29 2015 18:37:14
%S A093320 1,1,1,1,1,2,1,1,1,2,1,2,2,2,2,1,1,2,1,2,2,2,1,2,1,3,1,2,2,3,1,1,2,2,
%T A093320 2,2,2,2,3,2,2,3,2,2,2,2,2,2,1,2,2,3,1,2,2,2,2,3,1,3,2,2,2,1,3,3,1,2,
%U A093320 2,3,2,2,2,3,2,2,2,4,2,2,1,3,1,3,2,3,3,2,2,3,3,2,2,3,2,2,1,2,2,2,3,3,1,3,3
%N A093320 a(1) = 1; for m >= 2, a(m) = sum{p|m} a(pi(p)), where the sum is over the distinct prime divisors p of m and pi(p) is the order of p among the primes = the number of primes <= p.
%t A093320 PrimeFactors[n_Integer] := Flatten[ Table[ # [[1]], {1}] & /@ FactorInteger[n]]; a[1] = 1; a[n_] := a[n] = (Plus @@ (a[ # ] & /@ PrimePi[ PrimeFactors[n]])); Table[ a[n], {n, 105}] (* _Robert G. Wilson v_, May 04 2004 *)
%Y A093320 Cf. A093321, A066328, A094162 (for where n first appears).
%K A093320 nonn,easy
%O A093320 1,6
%A A093320 _Leroy Quet_, Apr 26 2004
%E A093320 More terms from _Robert G. Wilson v_, May 04 2004