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a(n) = the smallest squarefree integer >= the n-th prime power.
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%I #11 Oct 30 2017 22:39:23

%S 1,2,3,5,5,7,10,10,11,13,17,17,19,23,26,29,29,31,33,37,41,43,47,51,53,

%T 59,61,65,67,71,73,79,82,83,89,97,101,103,107,109,113,122,127,127,129,

%U 131,137,139,149,151,157,163,167,170,173,179,181,191,193,197,199,211

%N a(n) = the smallest squarefree integer >= the n-th prime power.

%C The first prime power is considered to be 1 here.

%H Michael De Vlieger, <a href="/A156898/b156898.txt">Table of n, a(n) for n = 1..10000</a>

%t Block[{nn = 216, s}, s = {1}~Join~Select[Range[nn], PrimePowerQ]; Map[SelectFirst[# + Range[0, #], SquareFreeQ] &, s]] (* _Michael De Vlieger_, Oct 30 2017 *)

%Y Cf. A081217, A156899, A156900, A005117, A000961.

%K nonn

%O 1,2

%A _Leroy Quet_, Feb 17 2009, Feb 18 2009

%E Extended by _Ray Chandler_, Jun 19 2009