Hello SeqFan,

could someone compute a few more terms of this seq:

 

1 12 14 155 160 211 271 292 419 548 572 691 ...

 

The principle is:

 

- Seq and first differences show the same "digit pattern".

 

S = 1 12 14 155 160 211 271 292 419 548 572 691 ...

d = 11 2 141 5 51 60 21 127 129 24 19 ...

 

Rules:

- start S with "1"

- add to the last term of S the smallest integer d no yet

added and not present in S such that the concatenation

of S's terms and the concatenation of all ds are the

same string of digits

 

So, never twice the same integer in sequence or first

differences.

 

I'm quite sure that all N's will be split between S and d.

 

Best,

.

 

http://www.research.att.com/~njas/sequences/A110621

has a close Mathematica pgm by Robert G. Wilson.

 

(thanks again to him!)