I searched a way to find out a formula to predict the nth number of a given sequence, but I did not find a way matching my case.
Arithmetic sequence:
I read that a good way is to find the constant difference.
Here is my sequence:
2,4,5,7,8,10,…
The differences are:
2,1,2,1,2,…
But I can't find a formula because the difference depends on the n variable and if the number is odd or even.
Docs I have read don't mention such case.
Best Answer
Try looking at the sequence as two separate sequences joined into one:
2,4,5,7,8,10...
=> 2,5,8,... and 4,7,10,...
If I denote the nth element in the original series as $a_n$, then :
If n is odd, $a_n = 2 + \frac{(n-1)}{2}*3$
If n is even, $a_n = 4 + \frac{n-2}{2}*3$