[seqfan] Digits of S differ by 1 (or 2, or 3...)

[Eric Angelini]

Hello SeqFans,
- S starts with 0;
- two consecutive digits of S always differ by 1;
- S is always extended with the smallest integer not yet in S:
S=0,1,2,3,4,5,6,7,8,9,87,65,43,21,23,45,67,89,876,54,32,10,12,34,56,78,98,76,543,210,101,212,121,232,123,...

T(0) shows a difference of 2 (between 2 consecutive digits):
T(0)=0,2,4,6,8,64,20,24,68,642,42,46,86,420,202,424,242,464,246,468,646,...

T(1) shows the same difference:
T(1)=1,3,5,7,9,75,31,35,79,753,13,57,97,53,135,313,131,353,531,357,535,757,575,797,579,...

Etc. A few other differences are possible (with other starts too).
My apologizes for the possible errors
in computing by hand these devilish seq.
Best,
É.