수열 15/2,24/5,35/10,48/17,63/26.

수열 15/2,24/5,35/10,48/17,63/26.

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)