That is 1 731+5 * 7 * 9 *1* n (n is 0,1,2,3, ...................................................).
That is 173 1+3465n (n is 0, 1, 2,3, ....................).
173 1= 5×346+ 1
173 1= 7×247+2
173 1= 9× 192+3
173 1= 1 1× 157+4
And 47 1 is wrong, because 47 1 =1× 42+9, that is, the remainder of 471divided by 1 1 is 9.