1, - 3,5, - 7,9, - 11... In this sequence, if the nth number is a, what is the nth + 1 number?

1, - 3,5, - 7,9, - 11... In this sequence, if the nth number is a, what is the nth + 1 number?

If n is odd, then the number n + 1 is - (a + 2);
If n is even, then the number n + 1 is - A + 2