A379602 a(n) is the least n-digit number whose square contains only digits greater than 5.

3, 26, 264, 3114, 25824, 260167, 2639867, 25845676, 260147437, 2582245083, 25843178924, 258241744863, 2582010592114, 25825761924437, 258218875510676, 2581990857627114, 25820083014911063, 258199298347206526, 2581988959445543367, 25819892911624938937, 258198891881411585714

Offset

1,1

Comments

Exists for all n because A379603(n) does (see Formulas there). - Michael S. Branicky, Dec 30 2024

Links

Table of n, a(n) for n=1..21.

Example

a(3) = 264 because among all 3-digit numbers, 264 is the smallest whose square 69696 contains only digits greater than 5.

Mathematica

f[m_] := For[k = Ceiling@Sqrt[100^m/15], k < 10^m - 1, k++, If[Min@IntegerDigits[k^2] > 5, Return[k]; ]]; Table[f[m], {m, 10}]

Crossrefs

Cf. A053972, A053974, A058471, A164778, A164772, A164773, A164841, A291631, A379603.

Sequence in context: A300398 A048861 A053972 * A204561 A126738 A283298

Adjacent sequences: A379593 A379594 A379595 * A379603 A379604 A379605

Keyword

nonn,base

Author

Zhining Yang, Dec 27 2024

Extensions

a(9) corrected and a(11) inserted by Michael S. Branicky, Dec 27 2024

More terms from Jinyuan Wang, Dec 27 2024

Status

approved