A048368 a(n)^3 is smallest cube containing exactly n 3's.

17, 7, 179, 477, 707, 6935, 15477, 44197, 535677, 693368, 2028209, 7566137, 32215777, 62446477, 322024127, 2027400657, 5171307877, 15373346477, 28575396477, 237304541491, 322033146477, 5105022776547, 4536383124177

Offset

1,1

Links

Table of n, a(n) for n=1..23.

Eric Weisstein's World of Mathematics, Cubic Number

Example

477^3 = 108531333 is the first cube containing four 3's, so a(4) = 477.

Mathematica

nsmall = Table[Infinity, 15];
For[i = 0, i <= 10^6, i++, n0 = Count[IntegerDigits[i^3], 3];
  If[nsmall[[n0]] > i, nsmall[[n0]] = i]];
Cases[nsmall, _?NumberQ] (* Robert Price, Mar 20 2020 *)

Crossrefs

Cf. A036530, A048365, A048366, A048367, A048369, A048370, A048371, A048372, A048373, A048374.

Sequence in context: A107807 A075710 A356060 * A040275 A355237 A033337

Adjacent sequences: A048365 A048366 A048367 * A048369 A048370 A048371

Keyword

nonn,base,more

Author

Patrick De Geest, Mar 15 1999

Extensions

a(14)-a(16) from Simon Nickerson (simonn(AT)maths.bham.ac.uk), Aug 12 2005

a(17)-a(20) from Lars Blomberg, Jun 12 2011

a(21)-a(23) from Giovanni Resta, Jun 29 2018

Status

approved