15 9 21 20 -25
-6 12 -1 -45
18 -13 -44
-31 -31
Differences didn't converge.
@Xarly
I will go with -25. This is my Final Answer, right or wrong! As I understand it, in Mathematics, Number Sequence Series should converge to Zero, otherwise you'll have an infinite sequence of the partial sums.
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