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 A251138 #5 Nov 30 2014 16:52:10 %S A251138 0,1,1,1,1,1,2,2,1,2,1,2,2,1,1,2,2,2,1,2,2,1,1,2,2,2,2,2,1,1,2,2,2,2, %T A251138 2,2,2,2,3,1,2,2,1,3,2,2,2,2,2,2,1,2,2,2,2,2,1,2,2,2,1,1,2,2,1,2,2,2, %U A251138 2,2,3,2,3,2,2,2,2,3,1,3,2,2,2,2,2,2 %N A251138 Number of distinct prime factors of A098550(n). %C A251138 a(n) = A001221(A098550(n)). %H A251138 Reinhard Zumkeller, <a href="/A251138/b251138.txt">Table of n, a(n) for n = 1..10000</a> %o A251138 (Haskell) %o A251138 a251138 = a001221 . fromIntegral . a098550 %Y A251138 Cf. A001221, A098548, A251139, A251140. %K A251138 nonn %O A251138 1,7 %A A251138 _Reinhard Zumkeller_, Nov 30 2014