[seqfan] Anagram sequence
David Wilson
davidwwilson at comcast.net
Thu Oct 20 07:17:37 CEST 2011
Let x and y be anagrams if they have the same digits, leading zeroes NOT
permitted.
For example, 104 and 410 are anagrams, 205 and 052 = 52 are not.
The sequence would be "Smallest positive integer with exactly n
anagrams", and starts
1 12 112 102 11112 123 1111112
f(n) = (10^n+8)/9 has n anagrams, so a(n) <= f(n). I believe a(n) = f(n)
for the primes and
certain other numbers.
I also believe f(n!) = A007908(n) for 1 <= n <= 9.
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