A202780 - OEIS

%I #29 Apr 18 2016 10:29:55

%S 7,108,335,6667,104636,333335,4504625,70585736,333333335,1818181815,

%T 33531510511,333333333335,198817904169

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

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

%t 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

%Y Cf. A161355.

%K base,more,nonn

%O 1,1

%A _Arkadiusz Wesolowski_, Jan 06 2012

%E a(9)-a(10) from _Donovan Johnson_, Jan 12 2012

%E a(11)-a(13) from _Giovanni Resta_, Apr 18 2016