(1) Let the general term be Cn=an/bn. The law of denominator is b 1 = 1, b2 = 3, bn = 2b (n- 1)+b (n-2). (n ≥ 3)。 (2) The law of molecular sequence is A 1 = 0, A2 = B 1+A 1, A3 = B2+A2, A4 = B3+A3, an = b (n-1)+a (n-. an =[( 1+√2)n-( 1-√2)n-2]/(2√2)。 (n = 1, 2, 3, ...) (3) There are numerator columns and denominator. Note: LZ, learn more basic knowledge, and it is better to do less such questions. I wish you progress.