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

1,1

Links

Table of n, a(n) for n=1..13.

Example

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

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

Crossrefs

Cf. A161355.

Sequence in context: A231519 A367157 A197447 * A297804 A218819 A033516

Adjacent sequences: A202777 A202778 A202779 * A202781 A202782 A202783

Keyword

base,more,nonn

Author

Arkadiusz Wesolowski, Jan 06 2012

Extensions

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

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

Status

approved