求 114514n114514^n114514n 的因子和 mod19260817mod 19260817mod19260817 , 192608171926081719260817 是质数, 114514114514114514 的质因子是 2,31,18472,31,18472,31,1847 。
2,12 ,12,1 31,131 ,131,1 1847,11847 ,11847,1 114514114514114514 的因子和为 s(2)∗s(31)∗s(1847)=3∗32∗1845=177120s(2)*s(31)*s(1847)=3*32*1845=177120s(2)∗s(31)∗s(1847)=3∗32∗1845=177120 如果 ppp 是素数 s(pn)=1+p+p2+...+pn=(p(n+1)−1)/(p−1)s(p^n)=1+p+p^2+...+p^n= (p^(n+1)-1) /(p-1)s(pn)=1+p+p2+...+pn=(p(n+1)−1)/(p−1) s(114514n)=s(2n)∗s(31n)∗s(1847n)s(114514^n)=s(2^n)*s(31^n)*s(1847^n)s(114514n)=s(2n)∗s(31n)∗s(1847n) a=s(2n)=2(n+1)−1a=s(2^n)=2^(n+1)-1a=s(2n)=2(n+1)−1 b=s(31n)=(31(n+1)−1)/30b=s(31^n)=(31^(n+1)-1)/30b=s(31n)=(31(n+1)−1)/30 c=s(1847n)=(1847(n+1)−1)/1846c=s(1847^n)=(1847^(n+1)-1)/1846c=s(1847n)=(1847(n+1)−1)/1846 303030 的逆元 109144631091446310914463 184618461846 的逆元 138769713876971387697 a=(pow(2,n+1,19260817)−1)%19260817a=(pow(2,n+1,19260817)-1)\%19260817a=(pow(2,n+1,19260817)−1)%19260817 b=(pow(31,n+1,19260817)−1)∗10914463)%19260817b=(pow(31,n+1,19260817)-1)*10914463)\%19260817b=(pow(31,n+1,19260817)−1)∗10914463)%19260817 c=(pow(1847,n+1,19260817)−1)∗1387697)%19260817c=(pow(1847,n+1,19260817)-1)*1387697)\%19260817c=(pow(1847,n+1,19260817)−1)∗1387697)%19260817 ans=(a∗b∗c)%19260817;ans=(a*b*c)\%19260817;ans=(a∗b∗c)%19260817; AC代码:
ll qpow(ll x, ll n, ll mod)
{
ll res = 1;
while (n)
{
if (n & 1)
res = (res * x) % mod;
x = x * x % mod, n >>= 1;
}
return res;
}
const int mod = 19260817;
int main()
{
int t;
int n;
sd(n);
ll a = (qpow(2, n + 1, mod) - 1) % mod;
ll inv1 = qpow(30, mod - 2, mod);
ll b = (((qpow(31, n + 1, mod) - 1) * inv1) % mod);
ll inv2 = qpow(1846, mod - 2, mod);
ll c = (((qpow(1847, n + 1, mod) - 1) * inv2) % mod);
ll ans = (a * b % mod * c % mod) % mod;
pld(ans);
return 0;
}
