[seqfan] 2 seqs with diffs distinct

N. J. A. Sloane njas at research.att.com
Sat Mar 27 17:05:01 CET 2010

i was talking to Richard Guy this morning and the following
sequences came up

we want A = a1 a2 a3 a4 ... and B = b1 b2 b3 ...
such that
1. all the terms are nonnegative integers 
2. The terms of A are strictly increasing
3. The terms of B are strictly increasing
4. All the numbers |A_i - B_j| are distinct

There are many solutions.  One might try looking for
the earliest A in lexicographic order. Or  , alternatively,
look for the earliest { A union B}, which is probably better.

Some scribbling suggests that we might end up with
A = 0 1 7 18 35 ...
B = 0 3 12 26 45 ...

Could someone program this up?

Neil (at the G4G9 conference)

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