This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A202780 #29 Apr 18 2016 10:29:55
%S A202780 7,108,335,6667,104636,333335,4504625,70585736,333333335,1818181815,
%T A202780 33531510511,333333333335,198817904169
%N A202780 Smallest number whose cube begins and ends with the same n digits, and with any other digit(s) in between.
%e A202780 335^3 = 37595375 starts and ends with the same 3 digits.
%t A202780 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 A202780 Cf. A161355.
%K A202780 base,more,nonn
%O A202780 1,1
%A A202780 _Arkadiusz Wesolowski_, Jan 06 2012
%E A202780 a(9)-a(10) from _Donovan Johnson_, Jan 12 2012
%E A202780 a(11)-a(13) from _Giovanni Resta_, Apr 18 2016