%I

%S 9,25,49,121,289,961,529,1194649,1849,5329,841,16129,7921,2209

%N The smallest square referenced in A237043 (Numbers n such that 2^n - 1 is not squarefree, but 2^d - 1 is squarefree for every proper divisor d of n.).

%e A273043(1)=6, 2^6-1=63, 63=3*3*7, 63 is not squarefree and the square is 3*3=9.

%Y Cf. A237043, A282632.

%K nonn

%O 1,1

%A _Robert Price_, Feb 19 2017