[seqfan] Add neighbours, use their digits

Eric Angelini Eric.Angelini at kntv.be
Sat Nov 2 10:22:01 CET 2013

Hello SeqFans,
this is a nightmare to compute by hand:
S = 1,10,2,19,73,100,3,20,4,39,54,...

Let R be a(n)+a(n+1)
We want R to be written with some (or
all) the digits belonging to a(n) or a(n+1) 
or both.
S is extended using the smallest
integer not yet present in S and
not leading to a contradiction.

We see here that 1+10=11 and yes,
the digits of 11 belong to {1,1,0}

Then 10+2=12 and yes, the digits
of 12 belong to {1,0,2}

Then 2+19=21 and yes, the digits
of 21 belong to {2,1,9}

Then 19+73=91 and yes, etc. 

I have absolutely no idea on how
to extend S. But I know that S is
infinite (because the trick 73+100=173 will work for ever).
Does someone have the patience
to check and extend S?
(my 6th term, "100", might be wrong).
Propulsé d'un aPhone

More information about the SeqFan mailing list