A253602 Numbers n such that the smallest exponent k for n and n^k to have common digits is 4.

22, 47, 92, 157, 187, 188, 192, 552, 558, 577, 707, 772, 922, 2522, 8338, 17177, 66888, 575757, 929522, 1717177, 8888588

Offset

1,1

Links

Table of n, a(n) for n=1..21.

Example

22^2=484 and 22^3=10648 have no digits in common with 22, but 22^4=234256 has some, so 22 is in the sequence.

Prog

(PARI) a253600(n) = {sd = Set(vecsort(digits(n))); k=2; while (#setintersect(sd, Set(vecsort(digits(n^k)))) == 0, k++); k; }
isok(n) = a253600(n) == 4;

Crossrefs

Cf. A029790, A103173, A189056, A253600, A253601.

Sequence in context: A250723 A044099 A044480 * A217751 A209186 A085381

Adjacent sequences: A253599 A253600 A253601 * A253603 A253604 A253605

Keyword

nonn,base,more

Author

Michel Marcus, Jan 05 2015

Status

approved