A048346 a(n)^2 is the smallest square containing exactly n 1's in its decimal notation.
0, 1, 11, 109, 1054, 3381, 10541, 105414, 414139, 1055041, 10252371, 78173596, 334082481, 1187901979, 1055036071, 33333407869, 105409293239, 718412219489, 1054501356619, 10536182856619, 105409445099152, 333331983425106, 1054092079569499, 10541257568071331, 37564758898655414, 33333331983425106
Offset: 0
Links
- Eric Weisstein's World of Mathematics, Square Number
Programs
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Mathematica
a[n_] := Block[{k=0}, While[DigitCount[k^2, 10, 1] != n, k++]; k]; Array[a, 8, 0] (* Giovanni Resta, Jul 27 2018 *)
Extensions
More terms from Jon E. Schoenfield, Jan 11 2009
Initial zero added by Zak Seidov, Nov 22 2010
a(17)-a(19) from Giovanni Resta, Jul 27 2018
a(20)-a(25) from Max Alekseyev, Mar 06 2025