The pattern would work better as signed operations. E.g.:
-2, +3, -4, +5...
+3, +4, +4, +5, +5...
And your head must really hurt from all the times you use "multiple" instead of "multiply". ;)
Note: you have the wrong pattern on 1 3 2 6 5 15 14 ? It should be:
x3, -1, x3, -1, x3, -1... |