[seqfan] Re: Canonical bijection from positive integers to positive rationals.

Peter Munn techsubs at pearceneptune.co.uk
Tue Mar 3 10:23:49 CET 2020

Update: Having found another nice bijection in A229994(n)/A077610(n), I
have listed this and others mentioned in this thread in the crossrefs for

If seqfans add any other bijective mappings that are in OEIS, then at some
point these can be copied to the other sequences.

Best Regards,

On Mon, March 2, 2020 8:08 pm, Peter Munn wrote:
> On Mon, March 2, 2020 4:58 pm, Peter Luschny wrote:
>> NS> For me, without doubt, the best map is the classic map based NS> on
the Stern's diatomic series (or Stern-Brocot sequence, A002487. For me
it is the Euclid tree: A295515.
> I cast my vote for the Sagher map, A071974(n)/A071975(n), which is
> multiplicative.
> Best Regards,
>  Peter
>> NS> from 1858: Look at all the references there.
>> Let's wait and see. In 160 years, we can count references again. If you
have Maple you can also try this delightful implementation:
>>     magic := x -> 1/(1 + floor(x) - frac(x)):
>> And then run:
>>     0; do magic(%) od;
>> Cheers, Peter
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