#include <bits/stdc++.h>

#define rep(i, j, k) for (int i = (j); i <= (k); ++i)
#define per(i, j, k) for (int i = (j); i >= (k); --i)
#define SZ(v) int((v).size())
#define ALL(v) (v).begin(),(v).end()
#define fi first
#define se second
using ll = long long;
using pii = std::pair<int, int>;
using pll = std::pair<ll, ll>;

template<class T>inline void chkmn(T &x, T y) { if (y < x) x = y; }
template<class T>inline void chkmx(T &x, T y) { if (y > x) x = y; }

using namespace std;

template <int P>
class mod_int {
  using Z = mod_int;

private:
  static int mo(int x) { return x < 0 ? x + P : x; }

public:
  int x;
  int val() const { return x; }
  mod_int() : x(0) {}
  template <class T>
  mod_int(const T &x_) : x(x_ >= 0 && x_ < P ? static_cast<int>(x_) : mo(static_cast<int>(x_ % P))) {}
  bool operator==(const Z &rhs) const { return x == rhs.x; }
  bool operator!=(const Z &rhs) const { return x != rhs.x; }
  Z operator-() const { return Z(x ? P - x : 0); }
  Z pow(long long k) const {
    Z res = 1, t = *this;
    while (k) {
      if (k & 1) res *= t;
      if (k >>= 1) t *= t;
    }
    return res;
  }
  Z &operator++() {
    x < P - 1 ? ++x : x = 0;
    return *this;
  }
  Z &operator--() {
    x ? --x : x = P - 1;
    return *this;
  }
  Z operator++(int) {
    Z ret = x;
    x < P - 1 ? ++x : x = 0;
    return ret;
  }
  Z operator--(int) {
    Z ret = x;
    x ? --x : x = P - 1;
    return ret;
  }
  Z inv() const { return pow(P - 2); }
  Z &operator+=(const Z &rhs) {
    (x += rhs.x) >= P && (x -= P);
    return *this;
  }
  Z &operator-=(const Z &rhs) {
    (x -= rhs.x) < 0 && (x += P);
    return *this;
  }
  Z &operator*=(const Z &rhs) {
    x = 1ULL * x * rhs.x % P;
    return *this;
  }
  Z &operator/=(const Z &rhs) { return *this *= rhs.inv(); }
#define setO(T, o)                                 \
  friend T operator o(const Z &lhs, const Z &rhs) {\
    Z res = lhs;                                   \
    return res o## = rhs;                          \
  }
  setO(Z, +) setO(Z, -) setO(Z, *) setO(Z, /)
#undef setO
};
const int P = 1e9 + 7;
using Z = mod_int<P>;

const int maxn = 1010;

int n, a[maxn];
Z f[75][75][75], g[75][75][75];
Z tf[75][75][75], tg[75][75][75];

int main() {
  cin.tie(nullptr) -> ios::sync_with_stdio(false);
  cin >> n;
  rep (i, 1, n) cin >> a[i];
  f[0][0][0] = 1, f[19][19][74] = 1, g[19][19][74] = 1;
  rep (i, 2, n) {
    rep (x, 0, 74) rep (y, x, 74) rep (z, y, 74) {
      tg[x][y][z] = g[x][y][z], tf[x][y][z] = f[x][y][z];
      f[x][y][z] = g[x][y][z] = 0;
    }
    rep (x, 0, 74) rep (y, x, 74) rep (z, y, 74) {
      int d = a[i] - a[i - 1];
      f[max(0, x - d)][max(0, y - d)][max(0, z - d)] += tf[x][y][z];
      g[max(0, x - d)][max(0, y - d)][max(0, z - d)] += tg[x][y][z];
      vector<pii> vec;
      if (x - d >= 0) vec.emplace_back(x - d, 0);
      if (y - d >= 0) vec.emplace_back(y - d, 1);
      if (z - d >= 0) vec.emplace_back(z - d, 2);
      vec.emplace_back(74, 3), vec.emplace_back(19, 1);
      int mn = 3, mx[3];
      for (auto [x, y] : vec) chkmn(mn, y);
      rep (i, 0, 2) mx[i] = 0;
      for (auto [x, y] : vec) if (y - mn < 3) chkmx(mx[y - mn], x);
      rep (i, 1, 2) chkmx(mx[i], mx[i - 1]);
      f[mx[0]][mx[1]][mx[2]] += tf[x][y][z];
      g[mx[0]][mx[1]][mx[2]] += tg[x][y][z] + mn * tf[x][y][z];
    }
  }
  Z ans = 0;
  rep (i, 0, 74) rep (j, 0, 74) rep (k, 0, 74) ans += g[i][j][k];
  cout << (ans * 2).val() << '\n';
}