A155146 - OEIS

A155146

Numbers n such that n^3 has exactly 3 different digits.

5, 6, 8, 9, 14, 15, 30, 36, 40, 62, 70, 92, 101, 110, 173, 192, 211, 300, 400, 700, 888, 1001, 1010, 1100, 1920, 3000, 3543, 4000, 7000, 8880, 10001, 10010, 10100, 11000, 19200, 30000, 35430, 40000, 70000, 88800, 100001, 100010, 100100, 101000, 110000, 110011

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

OFFSET

1,1

LINKS

Chai Wah Wu, Table of n, a(n) for n = 1..103

EXAMPLE

14 is in the list because 14^3 = 2744. - Jon Perry, Nov 04 2014

MAPLE

a := proc (n) if nops(convert(convert(n^3, base, 10), set)) = 3 then n else end if end proc: seq(a(n), n = 1 .. 150000); # Emeric Deutsch, Jan 27 2009

MATHEMATICA

Select[Range[120000], Length[Union[IntegerDigits[#^3]]]==3&] (* Vincenzo Librandi, Nov 04 2014 *)

PROG

(Python)

A155146_list, n3, m = [], 0, 0

for n in range(1, 10**7):

....m += 6*(n-1)

....n3 += m + 1

....if len(set(str(n3))) == 3:

........A155146_list.append(n) # Chai Wah Wu, Nov 03 2014

(Magma) [n: n in [0..120000] | #Set(Intseq(n^3)) eq 3]; // Vincenzo Librandi, Nov 04 2014

(PARI) is(n)=#Set(digits(n^3))==3 \\ Charles R Greathouse IV, Feb 11 2017