Instead of having each place worth b^n for some base b, they're worth n! each. Then given an n-tuple of numbers (1, ..., n), each digit of the number in factorial base tells which number to remove from the tuple and add to the permutation, e.g. 74 in base factorial is 24 06 02 01 3 0 1 0 (0,1,2,3)[3] = 3 (0,1,2)[0] = 0 (1,2)[1] = 2 (1)[0] = 1 so the permutation is (3,0,2,1). On Fri, Mar 18, 2016 at 5:31 PM, Dan Asimov <dasimov@earthlink.net> wrote:
How does that work, Mike?
—Dan
On Mar 18, 2016, at 11:36 AM, Mike Stay <metaweta@gmail.com> wrote:
"base factorial" gives an isomorphism between natural numbers and permutations.
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