A155146 Numbers k such that k^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

Offset: 1

Author

Dmitry Kamenetsky, Jan 21 2009

Keywords

• nonn
• base

Examples

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

Links

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

Crossrefs

Cf. A030292.

Programs

Magma

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

PARI

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

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

Extensions

Extended by Emeric Deutsch, Jan 27 2009