#include <bits/stdc++.h>
#define ff first
#define ss second
using namespace std;

typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

const int MOD = 1e9 + 7;
struct mint{
    int x;
    mint() : x(0) {}
    mint(int x) : x(x) {}
    mint operator+ (int ot) const { return x >= MOD - ot ? x - MOD + ot : x + ot; }
    mint operator- (int ot) const { return x >= ot ? x - ot : x - ot + MOD; }
    mint operator* (int ot) const { return 1ll * x * ot % MOD; }
    mint operator+= (int ot) { return *this = *this + ot; }
    mint operator-= (int ot) { return *this = *this - ot; }
    mint operator*= (int ot) { return *this = *this * ot; }
    operator int () const { return x; }
};

typedef tuple<int, int, int> tiii;

mint dp[2][76][76][76];
int main() {
    cin.tie(0); ios_base::sync_with_stdio(0);
    int n;
    cin >> n;
    int t[n];
    for (int i = 0; i < n; i++) cin >> t[i];
    
    vector<tiii> V;
    for (int z = 1; z <= 75; z++) {
        for (int y = 1; y <= (z == 75 ? 75 : z - 19); y++) {
            for (int x = 1; x <= (y == 75 ? 75 : y - 19); x++) {
                V.push_back({x, y, z});
            }
        }
    }

    mint pw[n + 1]{};
    pw[0] = 1;
    for (int i = 1; i <= n; i++) pw[i] = pw[i - 1] * 2;

    dp[0][75][75][75] = 1;
    int prv = 0;
    mint ans = 0;
    for (int i = 0; i < n; i++) {
        int k = t[i] - prv - 1;
        for (auto [x, y, z] : V) dp[1][x][y][z] = 0;
        for (auto [x, y, z] : V) dp[1][min(x + k, 75)][min(y + k, 75)][min(z + k, 75)] += dp[0][x][y][z];

        for (auto [x, y, z] : V) dp[0][x][y][z] = 0;
        for (auto [x, y, z] : V) {
            dp[0][min(x + 1, 75)][min(y + 1, 75)][min(z + 1, 75)] += dp[1][x][y][z];
            if (x <= 19 || z <= 74) {
                dp[0][min(x + 1, 75)][min(y + 1, 75)][min(z + 1, 75)] += dp[1][x][y][z];
            }
            else {
                dp[0][1][min(x + 1, 75)][min(y + 1, 75)] += dp[1][x][y][z];
            }
        }
        for (auto [x, y, z] : V) if (x == 1) ans += dp[0][x][y][z] * 2 * pw[n - 1 - i];
        // cout << "Round " << i << '\n';
        // for (auto [x, y, z] : V) {
        //     if (dp[0][x][y][z] != 0) {
        //         cout << x << ' ' << y << ' '<< z << " -> " << dp[0][x][y][z] << '\n';
        //     }
        // }
        prv = t[i];
    }
    cout << ans << '\n';
}