I used dp and this is my program:
var f:array[0..500,0..500]of extended;
    i,j,n:longint;
function min(a,b:longint):longint;
 begin
  if a<b then exit(a);
  exit(b);
 end;
begin
 readln(n);
 fillchar(f,sizeof(f),0);
 f[0,0]:=1;
 for i:=1 to n do
  for j:=1 to i do
   f[i,j]:=f[i,j-1]+f[i-j,min(j-1,i-j)];
 writeln(f[n,n]:0:0);
end.

But I want to know a faster algorithm,
could you please tell me?

let us suppose this is a building.
T[i][j] is the total number of buildings which uses i bricks, and its ground floor is exactly j.
O(n*logn).
AC code.
#include<iostream>
using namespace std;
__int64 T[501][35];
__int64 sum;
int n;
inline __int64 max(__int64 i,__int64 j)
{
    return i>j?i:j;
}
int main()
{
    int i,j,k;
    scanf("%d",&n);
    T[1][1]=1;
    for(i=2;i<=n;i++)
    {
        for(j=1;((j*(j+1))>>1)<=i;j++)
        {
            T[i][j]=T[i-j][j]+T[i-j][j-1];
        }
    }
    for(j=1;((j*(j+1))>>1)<=n;j++)
    {
        sum+=T[n][j];
    }
    printf("%I64d\n",sum-1);
    return 0;
}

sorry it's O(n^3/2)