%I #6 Aug 01 2013 05:01:02

%S 1,50,56,60,90,4900,5100,7500,7600,9900,12500,499000,501000,624000,

%T 625000,749000,751000,875000,999000,1249000,13427757,49990000,

%U 50010000,56250000,62490000

%N Numbers n such that n^3 has n as its middle digits.

%e a(6)=4900 because 4900^3 = 117649000000 has 4900 as its middle digits.

%t Do[If[StringPosition[ToString[n^3], ToString[n]][[1, 1]] == (Ceiling[Log[10, n^3]] - Ceiling[Log[10, n]]) / 2 + 1, Print[n]], {n, 0, 10^8}]

%Y Cf. A062118.

%K nonn,base

%O 1,2

%A _Vincenzo Librandi_, Jul 30 2013