A068360 - OEIS

%I #9 Jan 24 2013 14:30:51

%S 1,2,5,7,17,20,25,28,35,41,43,45,49,52,57,64,69,70,81,83,98,109,120,

%T 140,144,152,171,173,176,178,182,190,206,215,225,229,230,236,253,256,

%U 261,262,277,286,294,296,302,307,315,318,323,336,346,348,373,377,390

%N Numbers n such that there is no squarefree number between prime(n) and prime(n+1).

%H Harvey P. Dale, <a href="/A068360/b068360.txt">Table of n, a(n) for n = 1..1000</a>

%F n such that A061398(n)=0

%t Join[{1},PrimePi/@Transpose[With[{prs=Partition[Prime[Range[ 400]],2,1]}, Select[ prs,Union[SquareFreeQ/@Range[#[[1]]+1,#[[2]]-1]]=={False}&]]][[1]]] (* _Harvey P. Dale_, Jan 24 2013 *)

%Y Cf. A061398.

%K nonn

%O 1,2

%A _Benoit Cloitre_, Feb 28 2002