A030294 Numbers k such that k^3 has at most three different digits.

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 14, 15, 20, 30, 36, 40, 62, 70, 92, 100, 101, 110, 173, 192, 200, 211, 300, 400, 700, 888, 1000, 1001, 1010, 1100, 1920, 2000, 3000, 3543, 4000, 7000, 8880, 10000, 10001, 10010, 10100, 11000, 19200, 20000, 30000, 35430, 40000, 70000, 88800, 100000, 100001

Offset

1,3

Comments

While almost all larger terms have a regular digit pattern, there is the exception a(63) = 146796, a(63)^3 = A030295(63) = 3163316636166336. Are there other terms of this type? - Hugo Pfoertner, Feb 11 2020

Links

Hugo Pfoertner, Table of n, a(n) for n = 1..130

Mathematica

d3Q[n_]:=Count[DigitCount[n^3], _?(#>0&)]<4; Select[Range[0, 110000], d3Q] (* Harvey P. Dale, Mar 10 2016 *)
Select[Range[0, 101000], Count[DigitCount[#^3], 0]>6&] (* Harvey P. Dale, May 05 2023 *)

Prog

(Magma) [n: n in [0..400000] | #Set(Intseq(n^3)) le 3]; // Vincenzo Librandi, Nov 10 2014
(PARI) for(n=0, 10^9+1, if(#Set(digits(n^3))<=3, print1(n, ", "))); \\ Joerg Arndt, Dec 13 2014

Crossrefs

Cf. A030295.

Sequence in context: A191922 A230776 A252494 * A125668 A365472 A034894

Adjacent sequences: A030291 A030292 A030293 * A030295 A030296 A030297

Keyword

nonn,base

Author

Patrick De Geest

Status

approved