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

Offset

0,3

Comments

a(20) > 10^14. - Giovanni Resta, Jul 27 2018

Links

Table of n, a(n) for n=0..19.

Eric Weisstein's World of Mathematics, Square Number

Mathematica

a[n_] := Block[{k=0}, While[DigitCount[k^2, 10, 1] != n, k++]; k]; Array[a, 8, 0] (* Giovanni Resta, Jul 27 2018 *)

Crossrefs

Cf. A036508, A034978.

Sequence in context: A159495 A125423 A165149 * A054320 A287836 A124290

Adjacent sequences: A048343 A048344 A048345 * A048347 A048348 A048349

Keyword

nonn,base,more

Author

Patrick De Geest, Mar 15 1999

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

Status

approved