7節の問題 5 変化を表す表 (a)
| 式 | sum=-5 | n=0 | sum+=n | n+=2 | sum+=n | n+=2 | sum+=n |
| sum | -5 | . | -5 | . | -3 | . | -1 |
| n | . | 0 | . | 2 | . | 4 | . |
| 式 | k=0 | a=3 | pm=-1 | pm=-pm | k++ | a=2*a+pm*k*k | pm=-pm | k++ | a=2*a+pm*k*k | pm=-pm | k++ | a=2*a+pm*k*k |
| k | 0 | . | . | . | 1 | . | . | 2 | . | . | 3 | . |
| a | . | 3 | . | . | . | 5 | . | . | 6 | . | . | 17 |
| pm | . | . | -1 | 1 | . | . | -1 | . | . | 1 | . | . |
| 式 | k=1 | a=2 | pm=1 | pm=-pm | k++ | a=2*a+pm*k*k | pm=-pm | k++ | a=2*a+pm*k*k | pm=-pm | k++ |
| k | 1 | . | . | . | 2 | . | . | 3 | . | . | 4 |
| a | . | 2 | . | . | . | 0 | . | . | 9 | . | . |
| pm | . | . | 1 | -1 | . | . | 1 | . | . | 1 | . |
| 式 | k=1 | a=2 | pm=1 | pm=-pm | k++ | a=2*a+pm*k*k | pm=-pm | k++ | a=2*a+pm*k*k | pm=-pm | k++ |
| k | 1 | . | . | . | 2 | . | . | 3 | . | . | 4 |
| a | . | 2 | . | . | . | 0 | . | . | 9 | . | . |
| pm | . | . | 1 | -1 | . | . | 1 | . | . | 1 | . |