[seqfan] How many terms?

Eric Angelini Eric.Angelini at kntv.be
Mon Dec 8 10:02:23 CET 2014


Hello SeqFans,
How many terms could the longest such sequence S contain?
1) No term of S has a repeated digit (ex. 232 is forbidden)
2) a(n+1)=a(n)+[one digit of a(n)]
3) a(n+1)>a(n)

This S has 28 terms, for instance, and is impossible to extend:

S=1,2,4,8,16,17,18,19,28,36,39,42,46,52,54,58,63,69,75,82,84,92,94,98,106,107,108,109.

Start S' with any integer and try to beat 28.
Best,
É.



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