import std.conv, std.functional, std.range, std.stdio, std.string;
import std.algorithm, std.array, std.bigint, std.bitmanip, std.complex, std.container, std.math, std.mathspecial, std.numeric, std.regex, std.typecons;
import core.bitop;

class EOFException : Throwable { this() { super("EOF"); } }
string[] tokens;
string readToken() { for (; tokens.empty; ) { if (stdin.eof) { throw new EOFException; } tokens = readln.split; } auto token = tokens.front; tokens.popFront; return token; }
int readInt() { return readToken.to!int; }
long readLong() { return readToken.to!long; }
real readReal() { return readToken.to!real; }

bool chmin(T)(ref T t, in T f) { if (t > f) { t = f; return true; } else { return false; } }
bool chmax(T)(ref T t, in T f) { if (t < f) { t = f; return true; } else { return false; } }

int binarySearch(alias pred, T)(in T[] as) { int lo = -1, hi = cast(int)(as.length); for (; lo + 1 < hi; ) { const mid = (lo + hi) >> 1; (unaryFun!pred(as[mid]) ? hi : lo) = mid; } return hi; }
int lowerBound(T)(in T[] as, T val) { return as.binarySearch!(a => (a >= val)); }
int upperBound(T)(in T[] as, T val) { return as.binarySearch!(a => (a > val)); }


struct ModInt(int M_) {
  import std.conv : to;
  alias M = M_;
  int x;
  this(ModInt a) { x = a.x; }
  this(long a) { x = cast(int)(a % M); if (x < 0) x += M; }
  ref ModInt opAssign(long a) { return (this = ModInt(a)); }
  ref ModInt opOpAssign(string op)(ModInt a) {
    static if (op == "+") { x += a.x; if (x >= M) x -= M; }
    else static if (op == "-") { x -= a.x; if (x < 0) x += M; }
    else static if (op == "*") { x = cast(int)((cast(long)(x) * a.x) % M); }
    else static if (op == "/") { this *= a.inv(); }
    else static assert(false);
    return this;
  }
  ref ModInt opOpAssign(string op)(long a) {
    static if (op == "^^") {
      if (a < 0) return (this = inv()^^(-a));
      ModInt t2 = this, te = ModInt(1);
      for (long e = a; e > 0; e >>= 1) {
        if (e & 1) te *= t2;
        t2 *= t2;
      }
      x = cast(int)(te.x);
      return this;
    } else return mixin("this " ~ op ~ "= ModInt(a)");
  }
  ModInt inv() const {
    int a = x, b = M, y = 1, z = 0, t;
    for (; ; ) {
      t = a / b; a -= t * b;
      if (a == 0) {
        assert(b == 1 || b == -1);
        return ModInt(b * z);
      }
      y -= t * z;
      t = b / a; b -= t * a;
      if (b == 0) {
        assert(a == 1 || a == -1);
        return ModInt(a * y);
      }
      z -= t * y;
    }
  }
  ModInt opUnary(string op: "-")() const { return ModInt(-x); }
  ModInt opBinary(string op, T)(T a) const {
    return mixin("ModInt(this) " ~ op ~ "= a");
  }
  ModInt opBinaryRight(string op)(long a) const {
    return mixin("ModInt(a) " ~ op ~ "= this");
  }
  bool opCast(T: bool)() const { return (x != 0); }
  string toString() const { return x.to!string; }
}

enum MO = 10^^9 + 7;
alias Mint = ModInt!MO;

enum LIM = 2^^19 + 10;
Mint[] inv, fac, invFac;
void prepare() {
  inv = new Mint[LIM];
  fac = new Mint[LIM];
  invFac = new Mint[LIM];
  inv[1] = 1;
  foreach (i; 2 .. LIM) {
    inv[i] = -(Mint.M / i) * inv[cast(size_t)(Mint.M % i)];
  }
  fac[0] = invFac[0] = 1;
  foreach (i; 1 .. LIM) {
    fac[i] = fac[i - 1] * i;
    invFac[i] = invFac[i - 1] * inv[i];
  }
}
Mint binom(long n, long k) {
  if (0 <= k && k <= n) {
    assert(n < LIM);
    return fac[cast(size_t)(n)] * invFac[cast(size_t)(k)] * invFac[cast(size_t)(n - k)];
  } else {
    return Mint(0);
  }
}


int H;
int[] P;

int[] invP;
Mint[] prods, invProds;

Mint ans;

void doIt(int u, int l, int r) {
  alias Entry = Tuple!(int, "pos", int, "side");
  auto es = new Entry[r - l];
  const mid = (l + r) / 2;
  foreach (i; l .. r) {
    es[i - l] = Entry(P[i], (i < mid) ? 0 : 1);
  }
  es.sort;
  debug {
    writeln("u = ", u);
    writeln("  es = ", es);
  }
  
  auto sum = new Mint[][](2, r - l + 1);
  foreach (j; 0 .. r - l) {
    sum[0][j + 1] = sum[0][j];
    sum[1][j + 1] = sum[1][j];
    sum[es[j].side][j + 1] += prods[1 << (H - 1) | invP[es[j].pos]] * prods[1 << (H - 1) | es[j].pos];
  }
  debug {
    writeln("  sum = ", sum);
  }
  
  Mint tot;
  void dfs(int v, int l, int r, int a, int b) {
    if (b - a >= 1 && r - l > 1) {
      const mid = (l + r) / 2;
      const c = a + es[a .. b].lowerBound(Entry(mid, -1));
      Mint tmp;
      tmp += (sum[0][c] - sum[0][a]) * (sum[1][b] - sum[1][c]);
      tmp += (sum[1][c] - sum[1][a]) * (sum[0][b] - sum[0][c]);
      tmp *= invProds[v]^^2;
      tmp *= v;
      debug {
        writeln("  v = ", v, ", tmp = ", tmp, ", ans += ", tmp * invProds[u]^^2 * u);
      }
      tot += tmp;
      dfs(v << 1, l, mid, a, c);
      dfs(v << 1 | 1, mid, r, c, b);
    }
  }
  dfs(1, 0, 1 << (H - 1), 0, r - l);
  tot *= invProds[u]^^2;
  tot *= u;
  ans += tot;
}

void solve(int u, int l, int r) {
  if (r - l > 1) {
    doIt(u, l, r);
    const mid = (l + r) / 2;
    solve(u << 1, l, mid);
    solve(u << 1 | 1, mid, r);
  }
}

void main() {
  prepare;
  
  try {
    for (; ; ) {
      H = readInt();
      P = new int[1 << (H - 1)];
      foreach (i; 0 .. 1 << (H - 1)) {
        P[i] = readInt() - 1;
      }
      
      invP = new int[1 << (H - 1)];
      foreach (i; 0 .. 1 << (H - 1)) {
        invP[P[i]] = i;
      }
      
      prods = new Mint[1 << H];
      invProds = new Mint[1 << H];
      prods[1] = invProds[1] = 1;
      foreach (u; 2 .. 1 << H) {
        prods[u] = prods[u >> 1] * u;
        invProds[u] = invProds[u >> 1] * inv[u];
      }
      debug {
        writeln("prods = ", prods);
        writeln("invProds = ", invProds);
      }
      
      ans = 0;
      solve(1, 0, 1 << (H - 1));
      writeln(ans);
      
      debug {
        int lca(int u, int v) {
          for (; u != v; u >>= 1, v >>= 1) {}
          return u;
        }
        Mint brt;
        foreach (i; 0 .. 1 << (H - 1)) foreach (j; i + 1 .. 1 << (H - 1)) {
          const a = 1 << (H - 1) | i;
          const b = 1 << (H - 1) | j;
          const aa = 1 << (H - 1) | P[i];
          const bb = 1 << (H - 1) | P[j];
          const u = lca(a, b);
          const v = lca(aa, bb);
          Mint score = 1;
          score *= prods[a] * prods[aa];
          score *= prods[b] * prods[bb];
          score *= invProds[u]^^2;
          score *= invProds[v]^^2;
          score *= u;
          score *= v;
          writeln(i, " ", j, ": ", score);
          brt += score;
        }
        writeln("brt = ", brt);
        assert(brt.x == ans.x);
      }
    }
  } catch (EOFException e) {
  }
}


Measured memory_bytes: 26364