A248077 Least number k > 0 such that k^k contains exactly n distinct digits.

1, 3, 4, 5, 7, 14, 9, 11, 13, 19

Offset

1,2

Comments

Unlike A054039 and A247794, "...at least n..." and "...exactly n..." are two different sequences. a(n) above gives "...exactly n..." whereas, for "...at least n...", the sequence would be 1, 3, 4, 5, 7, 9, 9, 11, 13, 19, where a(6) would be 9 instead of 14.

Links

Table of n, a(n) for n=1..10.

Example

7^7 = 823543 has 5 distinct digits. 6^6, 5^5, 4^4, 3^3, 2^2, and 1^1 all do not have 5 distinct digits. So a(5) = 7.

Prog

(PARI)
a(n)=k=1; while(#vecsort(digits(k^k), , 8)!=n, k++); k
vector(10, n, a(n))

Crossrefs

Cf. A000312, A054039, A247794, A239306.

Sequence in context: A284618 A101759 A089560 * A239547 A060728 A330712

Adjacent sequences: A248074 A248075 A248076 * A248078 A248079 A248080

Keyword

nonn,base,fini,full,easy

Author

Derek Orr, Sep 30 2014

Status

approved