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 A243289 #18 Mar 04 2024 01:35:52
%S A243289 1,1,1,1,3,2,4,3,3,6,8,5,5,10,10,7,11,8,16,9,16,15,19,12,17,20,14,24,
%T A243289 15,21,16,25,17,29,27,26,20,20,28,34,36,23,34,40,25,25,35,43,43,28,38,
%U A243289 29,46,40,45,32,51,47,44,52,36,36,56,37,61,50,39,39,64,58
%N A243289 n minus the index of the greatest prime dividing n-th squarefree number: a(n) = n - A243290(n).
%C A243289 If A005117(n) <= 2n, or equally, if A243351 is always positive, then this sequence is certainly positive as well.
%H A243289 Antti Karttunen, <a href="/A243289/b243289.txt">Table of n, a(n) for n = 1..10000</a>
%F A243289 a(n) = n - A243290(n).
%t A243289 With[{t = Table[PrimePi[FactorInteger[k][[-1, 1]]], {k, Select[Range[120], SquareFreeQ]}]}, Range[Length[t]] - t] (* _Amiram Eldar_, Mar 04 2024 *)
%Y A243289 Cf. A005117, A006530, A049084, A243290, A243291, A243348, A243349, A243351.
%K A243289 nonn
%O A243289 1,5
%A A243289 _Antti Karttunen_, Jun 03 2014