[seqfan] 2n = a(n) minus next digit

[Eric Angelini]

Hello SeqFans,
2n = a(n) - [leftmost digit of a(n+1)]

B =  7,5,15,9,11,13,15,18,20,22,24,26, 29,31,33,35,38,40,42,44,46,49,51,
53,55,58,60,62,64,66,69,71,73,75,
78,80,82,...

The successive "gaps" are 2,4,6,8,
10,12,14,...

A "gap" is the difference between
an integer and the first digit of the
following one:

 7-5 gap 2
5-15 gap 4 = (5-1)
15-9 gap 6 
9-11 gap 8 = (9-1)
11-13 gap 10 = (11-1)
etc.

I hope B is the lexico-first such 
sequence -- can't prove though B won't stop somewhere...

Best,
É.