{"result":{"text":"a subscript r minus open parentheses table row n row 1 end table close parentheses a subscript r minus 1 plus open parentheses table row n row 1 end table close parentheses a subscript r minus 2 minus... plus open parentheses negative 1 close parentheses to the power of r a subscript 0 equals 0 space f o r"},"status":"ok"}