A243910 Least number k>0 such that 3^k contains exactly n different digits.

1, 3, 5, 7, 9, 13, 15, 24, 30, 39

Offset

1,2

Links

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

Example

3^7 = 2187 is the first power of 3 that contains 4 different digits. Thus a(4) = 7.

Prog

(PARI) a(n)=for(k=1, 10^3, st=2^k; if(#digits(st)>=n, c=0; for(i=0, 9, for(j=1, #digits(st), if(digits(st)[j]==i, c++; break))); if(c==n, return(k))))
n = 1; while(n<11, print1(a(n), ", "); n++)

Crossrefs

Sequence in context: A191182 A177855 A003524 * A211136 A178653 A222314

Adjacent sequences: A243907 A243908 A243909 * A243911 A243912 A243913

Keyword

nonn,base,full,fini

Author

Derek Orr, Jun 14 2014

Status

approved