switch (n) {
case 0:
case 0x00000001: case 0x00000002: case 0x00000004: case 0x00000008: case 0x00000010: case 0x00000020: case 0x00000040: case 0x00000080:
case 0x00000100: case 0x00000200: case 0x00000400: case 0x00000800: case 0x00001000: case 0x00002000: case 0x00004000: case 0x00008000:
case 0x00010000: case 0x00020000: case 0x00040000: case 0x00080000: case 0x00100000: case 0x00200000: case 0x00400000: case 0x00800000:
case 0x01000000: case 0x02000000: case 0x04000000: case 0x08000000: case 0x10000000: case 0x20000000: case 0x40000000: case 0x80000000:
　　return true;
default:
　　return false;
}