#include <stdio.h>
 
int main() {
    int a[33];
    int count = 0;
    a[0] = 2;
    a[1] = -1;
 
    for (int i = 2; i < 33; i++) {
        a[i] = -a[i - 1] + a[i - 2] + 2;
    }
 
    for (int i = 0; i < 33; i++) {
        if (a[i] > 1) { 
            int b = 1; 
            for (int j = 2; j * j <= a[i]; j++) {
                if (a[i] % j == 0) {
                    b = 0;
                    break;
                }
            }
            if (b) {
                count++;
            }
        }
    }
    printf("この数列のa0からa32までのうち、正で素数となっている項の個数は %d 個です。\n", count);
 
    return 0;
}

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