login
A385175
Cubes using at most three distinct digits, not ending in 0.
0
1, 8, 27, 64, 125, 216, 343, 512, 729, 1331, 2744, 3375, 46656, 238328, 778688, 1030301, 5177717, 7077888, 9393931, 700227072, 1003003001, 44474744007, 1000300030001, 1000030000300001, 1331399339931331, 3163316636166336, 1000003000003000001, 1000000300000030000001, 1000000030000000300000001
OFFSET
1,2
COMMENTS
This sequence has infinitely many terms since (10^m + 1)^3 is a term for all m >= 0.
Conjecture: a(26) = 3163316636166336 is the largest term with nonzero digits (See comments of A030294 and the data of A155146, where a(26) = A155146(47)^3).
FORMULA
a(n) = A202940(n)^3.
EXAMPLE
8, 343, and 46656 belong to this list because they are cubes that use 1, 2, and 3 distinct digits, respectively.
MATHEMATICA
Select[Range[10^6]^3, Length[Union[IntegerDigits[#]]]<4&&IntegerDigits[#][[-1]]!=0&] (* James C. McMahon, Jun 30 2025 *)
fQ[n_] := Mod[n, 10] > 0 && Length@ Union@ IntegerDigits[n^3] < 4; k = 1; lst = {}; While[k < 1000002, If[ fQ@k, AppendTo[lst, k]]; k++]; lst^3 (* Robert G. Wilson v, Jul 10 2025 *)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Gonzalo Martínez, Jun 20 2025
EXTENSIONS
a(28) from Robert G. Wilson v, Jul 10 2025
a(29) from David A. Corneth, Jul 10 2025
STATUS
approved