A154874 Numbers k such that k^3 contains every digit exactly twice.

2158479, 2190762, 2205528, 2219322, 2301615, 2330397, 2336268, 2345811, 2358828, 2359026, 2367609, 2388534, 2389119, 2389638, 2397132, 2428986, 2504736, 2524974, 2536152, 2583258, 2590125, 2607222, 2620827, 2622012, 2647866, 2649369, 2658636, 2671593

Offset

1,1

Comments

This sequence has 138 terms.

Links

Nathaniel Johnston, Table of n, a(n) for n = 1..138 (full sequence)

Example

2358828^3 = 13124683009764879552, which contains each digit 0..9 exactly twice.

Maple

lim:=floor((10^20)^(1/3)): for j from ceil((10^19)^(1/3)) to lim do d:=convert(j^3, base, 10): doubdig:=true: for k from 0 to 9 do if(numboccur(d, k)<>2)then doubdig:=false:break: fi: od: if(doubdig)then print(j); fi: od: # Nathaniel Johnston, May 28 2011

Mathematica

With[{cmin=Ceiling[Surd[10^19, 3]], cmax=Floor[Surd[10^20, 3]]}, Select[ Range[ cmin, cmax], Union[ DigitCount[#^3]]=={2}&]] (* Harvey P. Dale, Nov 17 2018 *)

Crossrefs

Cf. A054038, A074205, A154532, A154566, A154871, A154873.

Sequence in context: A253959 A253966 A253762 * A258421 A166930 A183754

Adjacent sequences: A154871 A154872 A154873 * A154875 A154876 A154877

Keyword

base,easy,fini,full,nonn

Author

Zhining Yang, Jan 16 2009

Status

approved