A036531 Smallest cube containing exactly n 4's.

0, 64, 2744, 1481544, 4410944, 444194947, 44474744007, 4970444443496, 2440744441344, 4408846444574424, 434424163454644544, 40045354844444494784, 304443494462464444459, 24144094248434404444864, 45444444436448021414449, 442063442345444443482444864

Offset: 0

Author

David W. Wilson

Keywords

• nonn
• base

Comments

a(n)^(1/3) = A048369(n) is the index of the first occurrence of n in sequence A269244. - M. F. Hasler, Feb 21 2016

Links

• Giovanni Resta, Table of n, a(n) for n = 0..22

Crossrefs

Cf. A048369, A036527, A036528, A036529, A036530, A036532, A036533, A036534, A036535, A036536.

Programs

Mathematica

nsmall = Table[Infinity, 20];
For[i = 0, i <= 10^6, i++, n0 = Count[IntegerDigits[i^3], 4];
  If[nsmall[[n0 + 1]] > i^3, nsmall[[n0 + 1]] = i^3]];
Cases[nsmall, ?NumberQ] (* _Robert Price, Mar 21 2020 *)

Formula

a(n) = A048369(n)^3. - M. F. Hasler, Feb 21 2016

Extensions

Extended with a(0) = 0 by M. F. Hasler, Feb 21 2016

a(11)-a(15) from Giovanni Resta, Jun 29 2018