A244603 Least number k such that n^k contains the digit n n times.

1, 18, 21, 32, 30, 38, 33, 55, 69

Offset

1,2

Links

Table of n, a(n) for n=1..9.

Example

2^18 is the first power of 2 to contain 2 twice. So a(2) = 18.
3^21 is the first power of 3 to contain 3 three times. So a(3) = 21.

Prog

(Python)
def tes(n):
  for k in range(1, 10**3):
    if(str(n**k).count(str(n))) == n:
      return k
n = 1
while n < 10:
  print(tes(n), end=', ')
  n += 1

Crossrefs

Sequence in context: A001101 A088341 A105145 * A120416 A293751 A090891

Adjacent sequences: A244600 A244601 A244602 * A244604 A244605 A244606

Keyword

nonn,base,fini,full

Author

Derek Orr, Jul 01 2014

Status

approved