[seqfan] Re: Extended with a pair of integers

[M. F. Hasler]

Eric,
Nice idea, but already there: A167151 (with correct 18+8=26).
--  Maximilian

On Sat, Oct 11, 2014 at 12:17 PM, Eric Angelini <Eric.Angelini at kntv.be> wrote:
>
> Hello SeqFans,
> S starts with 1 and is always extended with a pair of integers:
> - the first integer of the pair is the smallest integer not already in S;
> - the second integer is the sum of the two integers that preceed it.
>
> S=1
> S=1,2,3,
> S=1,2,3,4,7
> S=1,2,3,4,7,5,12
> S=1,2,3,4,7,5,12,6,18
> S=1,2,3,4,7,5,12,6,18,8,24
> S=1,2,3,4,7,5,12,6,18,8,24,9,33
> S=1,2,3,4,7,5,12,6,18,8,24,9,33,10,43
> etc.
> S is a permutation of the intergers > 0
> Every integer having an odd position in S
> is the sum of the two integers before it
> and the absolute difference of the two
> integers after it (except for 1, the first term of S):
> 3, for instance, is 1+2 and also |4-7|
> Best,
> É.