A036508 Smallest square containing exactly n 1's.

1, 121, 11881, 1110916, 11431161, 111112681, 11112111396, 171511111321, 1113111511681, 105111111121641, 6111111111571216, 111611104111115361, 1411111111712116441, 1113101111111117041, 1111116080161111121161, 11111119101145491111121, 516116117111111111421121

Offset: 1

Author

David W. Wilson

Keywords

• nonn
• base

Comments

a(17) > 4*10^23. - Jon E. Schoenfield, Jan 04 2009

a(20) > 10^28. - Giovanni Resta, Jul 27 2018

Links

• Giovanni Resta, Table of n, a(n) for n = 1..19

Crossrefs

Cf. A048346.

Programs

Mathematica

a[n_] := Block[{k=1}, While[DigitCount[k^2, 10, 1] != n, k++]; k^2]; Array[a, 7] (* Giovanni Resta, Jul 27 2018 *)

Extensions

a(13)-a(16) from Jon E. Schoenfield, Jan 05 2009

a(17) from Giovanni Resta, Jul 27 2018