%I #4 Apr 19 2019 09:05:57
%S 1,3,3,3,7,7,7,7,7,7,7,15,15,15,15,15,15,15,15,15,15,15,15,15,15,15,
%T 31,31,31,31,31,31,31,31,31,31,31,31,31,31,31,31,31,31,31,31,31,31,31,
%U 31,31,31,31,31,31,31,31,63,63,63,63,63,63,63,63,63,63,63,63,63,63,63,63
%N 2^n-1 written 2^n-1 times.
%t Table[Table[2^n-1,2^n-1],{n,6}]//Flatten (* _Harvey P. Dale_, Apr 19 2019 *)
%Y Cf. A000225.
%K nonn
%O 1,2
%A _Paul Curtz_, Nov 05 2007