1/a (n+1) = (1+3an)/an (reciprocal of both sides of the equation)

1/a(n+ 1)- 1/an = 3

So {1/an} is a arithmetic progression with1/a1as prime number and d=3 as tolerance.

1/an = 1+3(n- 1)= 3n-2

So an= 1/(3n-2)

This is a complete idea! ! ! I don't understand. Hi.