A common formula of 15 / 2,24 / 5,35 / 10,48 / 17,63 / 26 is--------------

A common formula of 15 / 2,24 / 5,35 / 10,48 / 17,63 / 26 is--------------

15/2=3*5/(1^2+1)
24/5=4*6/(2^2+1)
35/10=5*7/(3^2+1)
48/17=6*8/(4^2+1)
63/26=7*9/(5^2+1)
……
（n+2）*（n+4）/(n^2+1)

-1,8 / 5, - 15 / 7,24 / 9, - 35 / 11,48 / 13, then the 20th number in the sequence is?
Urgent need to use, if you know please reply ~!

440/41

A number sequence: 8, 17, 24, 35, what is the next number?

If it is a pure mathematical problem, then it is only 44; and the next number is 57; because 24-8 = 16; (the third number minus the first number) 35-17 = 18; (the fourth number minus the second number, jump subtraction) so the difference between the fifth number and the third number should be 20, so 24 + 20 = 44; it should not be wrong

Write a general term formula of the following series, so that the first few terms of them are the following numbers, the first question: - 1, 8 / 5, - 15 / 7, 24 / 9, - 35 / 11
Question 2: 1,0,1 / 3,0,1 / 5,0,1 / 7

Sn=(-1)^n*((n+1)^2-1)/(2n+1)