3968. The formula is the starting number squared, minus 1 (2*2-1=3...3*3-1=8....8*8-1=63..... 63*63-1=3968)
2 Add 1 to the number and then take the square root. 3968 + 1 = 3969 : √3969 = 63 63 + 1 = 64 : √64 = 8 8 + 1 = 9 : √9 = 3 3 + 1 = 4 : √4 = 2.
2 3 8 63
15745023
2
2 because sqrt(n+1) is the series.
63
63
129, 255, 513, 1023
35, 48, 63
500
11 comes next.