A126688 Lowest base in which n has distinct digits.

2, 2, 3, 4, 3, 3, 3, 4, 4, 5, 3, 4, 4, 4, 3, 5, 5, 4, 3, 5, 3, 5, 5, 4, 6, 6, 4, 4, 5, 4, 6, 6, 4, 6, 4, 4, 7, 5, 4, 5, 6, 5, 7, 4, 4, 7, 5, 5, 4, 4, 5, 4, 5, 4, 5, 4, 4, 5, 5, 6, 8, 6, 6, 9, 5, 5, 7, 6, 5, 5, 5, 7, 5, 7, 4, 5, 5, 4, 5, 5, 6, 5, 6, 5, 5, 5, 7, 7, 5, 6, 6, 8, 7, 6, 5, 5, 5, 8, 4, 11

Offset

1,1

Comments

Start with binary and work upwards, expressing n in the given base (2,3,4... b). The term a(n)=b is the lowest base in which no two digits in n are the same.

See A123699 for another version of the same sequence. - R. J. Mathar, Jun 15 2008

Links

Table of n, a(n) for n=1..100.

Example

75 is 1001011 in binary (base 2), 2210 in base 3 and 1023 in base 4. So a(75) = 4 since 1023 has distinct digits (and neither 1001011 nor 2210 do).

Crossrefs

Cf. A010784 (base 10), A062813 (gives lower bound for a term).

Sequence in context: A347865 A306606 A229989 * A350238 A352746 A330416

Adjacent sequences: A126685 A126686 A126687 * A126689 A126690 A126691

Keyword

nonn,base

Author

Paul Richards, Feb 15 2007

Status

approved