[seqfan] Add or subtract my cumulative sum of digits

[Éric Angelini]

Hello SeqFans,
start S with a(1) = 1 and now:
if a(n) is odd, add to a(n) the cumultive sum Q of the digits of S;
if a(n) is even, subtract Q from a(n) to get a(n+1); 

op  +  -   +  +   -  -   -   -    -    +    +    +   +   -    +    -
S = 1, 2, -1, 3, 10, 2, -8, -26, -52, -85, -39, 19, 87, 170,  79, 186, ...
Q = 1  3   4  7   8 10  18   26   33   46   58  68  83   91  107  122

Best,
É.