[seqfan] An old sequence from van der Poorten

[Neil Sloane]

Dear Seq Fans:

An old sequence suggested by a posting by Alf van der Poorten is A109732:
a(1) = 1; for n>1, a(n) is the smallest number not already present which is
entailed by the rules (i) k present => 2k+1 present; (ii) 3k present => k
present.
The open question is whether every odd number appears.

It seems that numbers of the form 2^k+1 take an exceptionally long time to
appear - see A261414, which needs more terms. In particular, when does 1025
appear in A109732?


Best regards
Neil

Neil J. A. Sloane, President, OEIS Foundation.
11 South Adelaide Avenue, Highland Park, NJ 08904, USA.
Also Visiting Scientist, Math. Dept., Rutgers University, Piscataway, NJ.
Phone: 732 828 6098; home page: http://NeilSloane.com
Email: njasloane at gmail.com