#include <stdio.h>
int main(void)
{
//数列a_nは常にa_n>a_(n-1)を満たす
//a_2 = 8
int a_l, a_m, a_n, count;
a_l = 1;
a_m = 2;
count = 0;
for(a_n = 8;a_n<=1000;a_n = 3*a_m + 2*a_l)
{
if(a_n>=100)
{
count++;
}
a_l = a_m;
a_m = a_n;
}
printf("100 <= a_n <= 1000 を与えるnは%d個ある",count
); return 0;
}
I2luY2x1ZGUgPHN0ZGlvLmg+CgppbnQgbWFpbih2b2lkKQp7CgkvL+aVsOWIl2FfbuOBr+W4uOOBq2Ffbj5hXyhuLTEp44KS5rqA44Gf44GZCgkvL2FfMiA9IDgKCWludCBhX2wsIGFfbSwgYV9uLCBjb3VudDsKCWFfbCA9IDE7CglhX20gPSAyOwoJY291bnQgPSAwOwoJZm9yKGFfbiA9IDg7YV9uPD0xMDAwO2FfbiA9IDMqYV9tICsgMiphX2wpCgl7CgkJaWYoYV9uPj0xMDApCgkJewoJCQljb3VudCsrOwoJCX0KCQlhX2wgPSBhX207CgkJYV9tID0gYV9uOwoJfQoJcHJpbnRmKCIxMDAgPD0gYV9uIDw9IDEwMDAg44KS5LiO44GI44KLbuOBryVk5YCL44GC44KLIixjb3VudCk7CglyZXR1cm4gMDsKfQo=