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 A010848 #11 Apr 10 2018 21:45:58 %S A010848 0,1,2,2,4,5,6,4,6,9,10,10,12,13,14,8,16,15,18,18,20,21,22,20,20,25, %T A010848 18,26,28,29,30,16,32,33,34,30,36,37,38,36,40,41,42,42,42,45,46,40,42, %U A010848 45,50,50,52,45,54,52,56,57,58,58,60,61,60,32,64,65,66,66,68,69,70,60 %N A010848 Number of numbers k <= n such that at least one prime factor of n is not a prime factor of k. %H A010848 Robert Israel, <a href="/A010848/b010848.txt">Table of n, a(n) for n = 1..10000</a> %F A010848 a(n) = n-A003557(n). - _Vladeta Jovovic_, Sep 15 2006 %p A010848 f:= n -> n - n/convert(numtheory:-factorset(n),`*`): %p A010848 map(f, [$1..100]); # _Robert Israel_, Apr 10 2018 %Y A010848 Cf. A008479, A010846, A010847. %K A010848 nonn,easy %O A010848 1,3 %A A010848 _Olivier Gérard_ %E A010848 Definition corrected by _Vladeta Jovovic_, Sep 15 2006