A227548 - OEIS

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

(list; graph; refs; listen; history; text; internal format)

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