A202780 Smallest number whose cube begins and ends with the same n digits, and with any other digit(s) in between.

7, 108, 335, 6667, 104636, 333335, 4504625, 70585736, 333333335, 1818181815, 33531510511, 333333333335, 198817904169

Offset: 1

Author

Arkadiusz Wesolowski, Jan 06 2012

Keywords

• base
• more
• nonn

Examples

			335^3 = 37595375 starts and ends with the same 3 digits.
		

Crossrefs

Cf. A161355.

Programs

Mathematica

lst = {}; Do[n = Ceiling[(10^(2*k))^(1/3)]; While[True, d = IntegerDigits[n^3]; If[Take[d, k] == Take[d, -k], Break[]]; n++]; AppendTo[lst, n], {k, 6}]; lst

Extensions

a(9)-a(10) from Donovan Johnson, Jan 12 2012

a(11)-a(13) from Giovanni Resta, Apr 18 2016