A227548 Numbers n such that n^3 has n as its middle digits.

1, 50, 56, 60, 90, 4900, 5100, 7500, 7600, 9900, 12500, 499000, 501000, 624000, 625000, 749000, 751000, 875000, 999000, 1249000, 13427757, 49990000, 50010000, 56250000, 62490000

Offset

1,2

Links

Table of n, a(n) for n=1..25.

Example

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

Mathematica

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}]

Crossrefs

Cf. A062118.

Sequence in context: A118146 A349210 A114504 * A282112 A172468 A046832

Adjacent sequences: A227545 A227546 A227547 * A227549 A227550 A227551

Keyword

nonn,base

Author

Vincenzo Librandi, Jul 30 2013

Status

approved