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%I #12 Aug 13 2024 02:23:47
%S 1,2,3,12,6,7,10,24,25,14,15,32,19,21,22,45,26,49,30,52,33,34,35,63,
%T 64,39,72,75,43,46,47,84,53,55,57,96,59,61,62,104,66,67,69,117,120,73,
%U 74,125,126,128,82,135,85,140,87,147,91,93,94,153,97,101,162,164,105,106
%N a(1) = 1, a(n) = n-th squarefree number if n is squarefree else a(n) is the n-th nonsquarefree number.
%e a(4) = 12, the 4th nonsquarefree number.
%o (Python)
%o # uses programs from A005117 and A013929
%o from sympy import factorint
%o def A088611(n): return A005117(n) if max(factorint(n).values(),default=0)<2 else A013929(n) # _Chai Wah Wu_, Aug 12 2024
%Y Cf. A088612, A005117, A013929.
%K nonn
%O 1,2
%A _Amarnath Murthy_, Oct 16 2003
%E Corrected and extended by _Ray Chandler_, Oct 18 2003