Count number of arithmetic sequences in an array
“Arithmetic” means, from an array with at least 3 values, the difference from one value to the next one remains the same.
eg. [-1,1,3, 5] is arithmetic. [-1,1, 3, 3] is not.
First attempt under the gun of a timed challenge took an hour, almost had a working solution. Code deleted.
Second attempt a few days later, <30 min. Solved. Some recursiveness thrown in there.











