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
Examples
a(3) = 264 because among all 3-digit numbers, 264 is the smallest whose square 69696 contains only digits greater than 5.
Programs
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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}]
Extensions
a(9) corrected and a(11) inserted by Michael S. Branicky, Dec 27 2024
More terms from Jinyuan Wang, Dec 27 2024
Comments