A247045 Triangle read by rows: T(n,k) = least number m > 0 such that m^k in base n contains exactly k distinct digits, 1 <= k <= n.

1, 1, 2, 1, 3, 4, 1, 2, 3, 5, 1, 3, 3, 6, 12, 1, 3, 5, 7, 7, 15, 1, 3, 5, 9, 5, 17, 15, 1, 4, 5, 10, 9, 7, 11, 33, 1, 3, 5, 7, 11, 19, 14, 16, 53, 1, 4, 5, 6, 7, 13, 13, 14, 21, 36, 1, 4, 5, 7, 10, 8, 12, 12, 16, 42, 41, 1, 4, 6, 16, 11, 8, 19, 19, 16, 28, 35, 55, 1, 4, 6, 9, 9, 14, 10, 18, 14

Offset

1,3

Links

Indranil Ghosh, Rows 1..36 of triangle, flattened

Example

T(n,k) is given by (row n corresponds to base n):
1;
1, 2;
1, 3, 4;
1, 2, 3,  5;
1, 3, 3,  6, 12;
1, 3, 5,  7,  7, 15;
1, 3, 5,  9,  5, 17, 15;
1, 4, 5, 10,  9,  7, 11, 33;
1, 3, 5,  7, 11, 19, 14, 16, 53;
1, 4, 5,  6,  7, 13, 13, 14, 21, 36; (base 10)
1, 4, 5,  7, 10,  8, 12, 12, 16, 42, 41;
Example: T(7,3) = 5 means that 5 is the smallest number such that 5^3 in base 7 (which is 125 in base 7 = 236) has 3 distinct digits (2, 3, and 6).

Prog

(PARI)
print1(1, ", "); n=2; while(n<20, m=1; for(k=1, n, while(m, d=digits(m^k, n); if(#vecsort(d, , 8)!=k, m++); if(#vecsort(d, , 8)==k, print1(m, ", "); m=1; break))); n++)

Crossrefs

Cf. A016069, A155146, A155150.

Sequence in context: A279396 A161224 A147567 * A347354 A361429 A345290

Adjacent sequences: A247042 A247043 A247044 * A247046 A247047 A247048

Keyword

nonn,base,tabl

Author

Derek Orr, Sep 10 2014

Status

approved