Question

初中数学题。过来！！！！！！！

第一步：取一个自然数n1=5计算n1的2次方的a1；
第二步：算出a1的各位数字之和的n2，计算n2的2次方+1得a2；
第三步：算出a2的各位数字之和的n3，在计算n3的2次方+1得a3；
······依此类推，则a2008=多少？
求解啊！！！！！！！！！！！！！！！！！！！！！！！！！！

Answer 1

n1 = 5 a1 = 5*5 = 25
n2 = 2+5 = 7 a2 = 7*7+1 = 50

n3 = 5+0 = 5 a3 = 5*5+1 = 26
n4 = 2+6 = 8 a4 = 8*8+1 = 65
n5 = 6+5 = 11 a5 = 11*11+1 = 122

n6 = 1+2+2 = 5 a6 = 5*5+1 = 26
n7 = 2+6 = 8 a7 = 8*8+1 = 65
n8 = 6+5 = 11 a8 = 11*11+1 = 122

n9 = 1+2+2 = 5 a9 = 5*5+1 = 26
n10 = 2+6 = 8 a10 = 8*8+1 = 65
n11 = 6+5 = 11 a11 = 11*11+1 = 122

每3个循环一次

2008=2+3*668+2 即在a1a2和668次循环后的第2个
所以a2008=65

Answer 2

n1 = 5 a1 = 5*5 = 25
n2 = 2+5 = 7 a2 = 7*7+1 = 50

n3 = 5+0 = 5 a3 = 5*5+1 = 26
n4 = 2+6 = 8 a4 = 8*8+1 = 65
n5 = 6+5 = 11 a5 = 11*11+1 = 122

n6 = 1+2+2 = 5 a6 = 5*5+1 = 26
……
循环 后面的你懂得

Answer 3

n1 = 5 a1 = 5*5 = 25
n2 = 2+5 = 7 a2 = 7*7+1 = 50

n3 = 5+0 = 5 a3 = 5*5+1 = 26
n4 = 2+6 = 8 a4 = 8*8+1 = 65
n5 = 6+5 = 11 a5 = 11*11+1 = 122
n6 = 1+2+2 = 5 a6 = 5*5+1 = 26
(2008-3+1)/3=668......1
a2008=a4=65