, a pandigital number
is an integer that in a given base has among its significant digits each digit used in the base at least once. For example, 1223334444555567890 is a pandigital number in base 10. The first few pandigital base 10 numbers are given by :
1023456789, 1023456798, 1023456879, 1023456897, 1023456978, 1023456987, 1023457689
The smallest pandigital number in a given base b
is an integer of the form
<math>b^ + sum_^ db^</math>
The following table lists the smallest pandigital numbers of a few selected bases:
gives the base 10 values for the first 18 bases.
In a trivial sense, all positive integers are pandigital in unary (or tallying). In binary, all integers are pandigital except for 0 and numbers of the form <math>2^n - 1</math> (the Mersenne number
). The larger the base, the rarer pandigital numbers become, though one can always find runs of <math>b^x</math> consecutive pandigital numbers with redundant digits by writing all the digits of the base together (but not putting the zero first as the most significant digit) and adding x
+ 1 zeroes at the end as least significant digits.
Conversely, the smaller the base, the fewer pandigital numbers without redundant digits there are. 2 is the only such pandigital number in base 2, while there are more of these in base 10.
Sometimes, the term is used to refer only to pandigital numbers with no redundant digits. In some cases, a number might be called pandigital even if it... Read More