A239437 Least number that is pandigital in some base >= n but not pandigital in bases 3 through n-1.

11, 78, 698, 12280, 179685, 5518135, 1037845296, 1037845296, 46935813565, 2860727439460, 285947759601954, 1018897102759406, 672654273047783383

Offset

3,1

Comments

Gives an upper bound on the testing needed to check membership in A239348.

Links

Table of n, a(n) for n=3..15.

Charles R Greathouse IV, GP script for computing terms

Formula

Trivially a(n) >= A049363(n) > n^(n-1).

Prog

(PARI) See Greathouse link.
(Python)
from itertools import permutations
from gmpy2 import digits
def A239437(n): # requires 3 <= n <= 62
....m = n
....while True:
........s = ''.join([digits(i, m) for i in range(m)])
........for d in permutations(s, m):
............if d[0] != '0':
................c = mpz(''.join(d), m)
................for b in range(3, n):
....................if len(set(digits(c, b))) == b:
........................break
................else:
....................return int(c)
........m += 1 # Chai Wah Wu, May 31 2015

Crossrefs

Subsequence of A154314. Cf. A239348.

Sequence in context: A041224 A030054 A225896 * A140542 A101983 A139953

Adjacent sequences: A239434 A239435 A239436 * A239438 A239439 A239440

Keyword

nonn,base,hard

Author

Charles R Greathouse IV, Mar 18 2014

Extensions

a(15) from Giovanni Resta, Mar 19 2014

Status

approved