%I #10 May 12 2017 17:36:51
%S 1,11,111,1111,11111,111111,1111111,11111111,111111111,
%T 1010101010101010101,101010101010101010101,10101010101010101010101,
%U 1010101010101010101010101,101010101010101010101010101
%N a(n) = concatenation of n n times divided by n.
%p seq(seq(sum(10^((l+1)*(j-1)),j=1..i),i=10^l..10^(l+1)-1),l=0..1);
%t Table[FromDigits[Flatten[IntegerDigits/@Table[n,n]]]/n,{n,20}] (* _Harvey P. Dale_, May 12 2017 *)
%Y Cf. A000461
%K base,nonn
%O 1,2
%A _Amarnath Murthy_, Nov 21 2002
%E More terms from _Sascha Kurz_, Jan 04 2003