A084688 Nonnegative integers n such that 2^n uses only distinct decimal digits.

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 20, 29

Offset: 1

Author

Zak Seidov, Jul 01 2003

Keywords

• fini
• nonn
• full
• base

Comments

There are exactly 18 numbers such that 2^n uses only distinct digits.

a(n) can have at most 10 digits. As 2^34 has 11 digits, a(n) < 34. - David A. Corneth, Aug 03 2015

Subsequence of A052060. - R. J. Mathar, Sep 17 2008

Examples

			29 is the last term with 2^29 = 536870912 = A260814(18). - _Zak Seidov_, Aug 02 2015
		

Crossrefs

Cf. A000079, A260814, A052060.

Programs

Mathematica

Select[Range[0, 34], Max@ DigitCount[2^#] == 1 &] (* Michael De Vlieger, Aug 03 2015 *) (* with corrections by Zak Seidov, Aug 05 2015 *)

PARI

lista() = {lim = ceil(log(10^11)/(log(2)));for (n=0, lim, d = digits(2^n); if (#vecsort(d,,8) == #d, print1(n, ", ")););} \\ Michel Marcus, Aug 03 2015

Formula

a(n) = log_2(A260814(n)). - Zak Seidov, Aug 02 2015