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%I #21 Oct 10 2019 23:36:06
%S 0,1,11,109,1054,3381,10541,105414,414139,1055041,10252371,78173596,
%T 334082481,1187901979,1055036071,33333407869,105409293239,
%U 718412219489,1054501356619,10536182856619
%N a(n)^2 is the smallest square containing exactly n 1's in its decimal notation.
%C a(20) > 10^14. - _Giovanni Resta_, Jul 27 2018
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/SquareNumber.html">Square Number</a>
%t a[n_] := Block[{k=0}, While[DigitCount[k^2, 10, 1] != n, k++]; k]; Array[a, 8, 0] (* _Giovanni Resta_, Jul 27 2018 *)
%Y Cf. A036508, A034978.
%K nonn,base,more
%O 0,3
%A _Patrick De Geest_, Mar 15 1999
%E More terms from _Jon E. Schoenfield_, Jan 11 2009
%E Initial zero added by _Zak Seidov_, Nov 22 2010
%E a(17)-a(19) from _Giovanni Resta_, Jul 27 2018
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