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A239437 Least number that is pandigital in some base >= n but not pandigital in bases 3 through n-1. 1
11, 78, 698, 12280, 179685, 5518135, 1037845296, 1037845296, 46935813565, 2860727439460, 285947759601954, 1018897102759406, 672654273047783383 (list; graph; refs; listen; history; text; internal format)
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

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Last modified October 18 05:31 EDT 2019. Contains 328146 sequences. (Running on oeis4.)