let split_string ?(pattern=" ") = Str.split @@ Str.regexp pattern
let n = Scanf.sscanf (read_line ()) "%d" @@ fun n -> n
let ls = read_line () |> split_string |> List.map int_of_string |> List.sort compare |> Array.of_list

let rec loop ai bi l r =
  if r <= l then begin
    let l = ref l in
    while !l < n - 1 && ls.(!l + 1) = ls.(!l) do l := !l + 1 done;
    max 0 @@ !l - bi - 1
  end
  else
    let mid = (l + r) / 2 in
    let a, b, c = ls.(ai), ls.(bi), ls.(mid) in
    if a < b + c && b < c + a && c < a + b then loop ai bi (mid + 1) r
    else loop ai bi l mid

let () =
  let ans = ref 0 in
  for i = 0 to n - 3 do
    for j = i + 1 to n - 2 do
      ans := !ans + loop i j (j + 1) n
    done
  done;
  Printf.printf "%d\n" !ans