A036516 Smallest square containing exactly n 9's.

9, 3969, 29929, 1999396, 299739969, 2909199969, 19299599929, 909995799969, 9499999990849, 999999202999696, 9969959993997969, 90949999999997329, 9199999971969929929, 199999969997999200969, 19997911999199999979409, 295191999919994299999969

Offset

1,1

Comments

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

Links

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

Mathematica

a[n_] := Block[{k=1}, While[DigitCount[k^2, 10, 9] != n, k++]; k^2]; Array[a, 6] (* Giovanni Resta, Jul 27 2018 *)

Crossrefs

Cf. A048354. - Jon E. Schoenfield, Jan 24 2009

Sequence in context: A222948 A281876 A046896 * A024126 A163018 A193310

Adjacent sequences: A036513 A036514 A036515 * A036517 A036518 A036519

Keyword

nonn,base

Author

David W. Wilson

Extensions

More terms from Jon E. Schoenfield, Jan 24 2009

a(16) from Giovanni Resta, Jul 27 2018

Status

approved