1+6/19+12/61+20/141+30/271+42/463
=(1+3+5+7+9+11)+(6/1+12/1+30/1+42/1)
=36+(2/1-3/1+3/1-4/1+4/1-5/1+5/1-6/1+6/1-7/1)
=36+(2/1-7/1)
=36+14/5
=36又14/5