#define ATCODER #define _USE_MATH_DEFINES #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include using namespace std; using ll = long long; using ld = long double; using pll = pair; using pdd = pair; #define FOR(i, a, b) for (ll i = (a); i < (b); i++) #define REP(i, n) for (ll i = 0; i < (n); i++) #define ROF(i, a, b) for (ll i = (b - 1); i >= (a); i--) #define PER(i, n) for (ll i = n - 1; i >= 0; i--) #define VL vector #define VVL vector> #define VP vector> #define LPQ(T) priority_queue, greater> #define all(i) begin(i), end(i) #define SORT(i) sort(all(i)) #define BITI(i) (1 << i) #define BITSET(x, i) x | (ll(1) << i) #define BITCUT(x, i) x & ~(ll(1) << i) #define EXISTBIT(x, i) (((x >> i) & 1) != 0) #define ALLBIT(n) (ll(1) << n - 1) #define CHMAX(n, v) n = n < v ? v : n #define CHMIN(n, v) n = n > v ? v : n #define MP(a, b) make_pair(a, b) #define DET2(x1, y1, x2, y2) x1 *y2 - x2 *y1 #define DET3(x1, y1, z1, x2, y2, z2, x3, y3, z3) x1 *y2 *z3 + x2 *y3 *z1 + x3 *y1 *z2 - z1 *y2 *x3 - z2 *y3 *x1 - z3 *y1 *x2 #define INC(a) \ for (auto &v : a) \ v++; #define DEC(a) \ for (auto &v : a) \ v--; #define SQU(x) (x) * (x) #ifdef ATCODER #include using namespace atcoder; using mint = modint1000000007; using mint2 = modint998244353; #endif template vector read(size_t n) { vector ts(n); for (size_t i = 0; i < n; i++) cin >> ts[i]; return ts; } template void read_tuple_impl(TV &) {} template void read_tuple_impl(TV &ts) { get(ts).emplace_back(*(istream_iterator(cin))); read_tuple_impl(ts); } template decltype(auto) read_tuple(size_t n) { tuple...> ts; for (size_t i = 0; i < n; i++) read_tuple_impl(ts); return ts; } using val = ll; using func = ll; val op(val a, val b) { return max(a, b); } val e() { return -1e18; } val mp(func f, val a) { return a + f; } func comp(func f, func g) { return f + g; } func id() { return 0; } ll di[4] = {1, 0, -1, 0}; ll dj[4] = {0, 1, 0, -1}; ll si[4] = {0, 3, 3, 0}; ll sj[4] = {0, 0, 3, 3}; // ll di[4] = { -1,-1,1,1 }; // ll dj[4] = { -1,1,-1,1 }; ll di8[8] = {0, -1, -1, -1, 0, 1, 1, 1}; ll dj8[8] = {-1, -1, 0, 1, 1, 1, 0, -1}; template void Factorical(ll siz, vector& out) { out.resize(siz + 1); out[0] = T(1); for (ll i = 0; i < siz; i++) { out[i + 1] = out[i] * (i + 1); } } template T Combi(ll a, ll b, vector& fact) { return fact[a] / (fact[b] * fact[a - b]); } void solve() { ll n; cin>>n; VL a=read(n); mint2 ans=0; mint2 half=mint2(1)/2; REP(i,n){ ll L=i; ll R=n-i-1; mint2 add=mint2(L+2)*mint2(2).pow(L)*half; add*=mint2(R+2)*mint2(2).pow(R)*half; ans+=add*a[i]; } cout<> t; while (t--) { solve(); } return 0; }