[seqfan] Rigidity of an okapi

[Éric Angelini]

Hello SeqFans,
When they want to write a constrained text, 
French oulipians obey sometimes the "Rigidité
de l'okapi" command -- a whole text where 
consonants and vowels alternate (the okapi
alternates bright and dark stripes).

This sequence alternates odd and even digits,
-- and so do the "first additions" when they
are considered as a sequence.

I need help to correct and extend S (which
should be the lexicographically first "okapi"
seq with no duplicated term):

S = 1,29,21,49,23,27,25,45,47,43,2967,63,2947,65,...

"First additions" are:

F = 30,50,70,72,50,52,70,92,90,3010,3030,3010,3012,...

Both S and F have digits following the pattern
odd/even/odd/even/odd...

I have computed by hand smthg like 35 terms -- 
(a nightmare) but I made so many mistake during
the process that I prefer to send the above start
only (in hope that those few terms are ok).

A question I cannot answer: will a 3-digit term
appear at some point?

Another one:
Is it possible to start an "okapi sequence" with
a(1) = 2?
Thank you in advance,
Best,
É.