Find sequence 1 + 1, 1A + 4, 1A2 + 7, 1A3 + 10 ，1an-1+（3n-2），… The sum of the first n terms of

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• 1. If n is an integer and y = n + 3N ＾ 2 + 2n ＾ 3, we prove that y is a multiple of 6
• 2. Prove n + (n + 1) + (n + 2)... + 2n = 3N (n + 1) / 2 by induction
• 3. Given 3 ^ m = 2, 3N ^ = 4, find the value of 9 ^ m + 1-2n
• 4. 3 × 9 ^ n × 27 ^ n-1 = 3 x 3 ^ 2n x 3 ^ (3n-3)
• 5. If the 2nth power of x = 3, find the value of the fourth power of (- 1 / 3 x to the 3nth power) / [the 2nth power of 4 (X & # 179;)]
• 6. What are the number of items and times in a ^ 3-A ^ 2b-b ^ 3, 3N ^ 4-2n ^ 2 + 1?
• 7. It is stipulated that an operation on positive integer n, whose rule is: F (n) = 3N + 1 (n is odd) 2n − 1 (n is even), then f (3)=______ ，f[f（1）]=______ ．
• 8. What is the answer to an h-operation with odd number 3N = 13 and even number * 1 / 2 until odd number 257?
• 9. It is stipulated that the "H operation" of positive integer n is: ① when n is odd, H = 3N + 13; ② when n is even, H = NX1 / 2x1 / 2 Where h is odd For example, the result of number 3 after one "H operation" is 22, the result after two "H operations" is 11, and the result after three "H operations" is 46 (1) Find 257, after 257 times of "H operation" to get the result (2) If the result of "H operation" is always constant a, find the value of A I want to solve the problem
• 10. Let a = {x | x = 2n + 1, n ∈ n}, B = {x | 1 ≤ x ≤ 10}, C = {x | x = 3N, n ∈ n}, find (a ∩ b) ∩ C
• 11. If Sn = 2n ^ 2 + 3n-4, then an=____
• 12. An = 3N ^ 2-2n + 1 for Sn =?
• 13. Sum: 1 + 45 + 752 + +3n−25n−1．
• 14. Let Sn = 1 * 4 + 2 * 7 +. N (3N + 1), then SN=
• 15. 1/(1*4)+1/(4*7)+1/(7*10)+…… +1 / [(3n-2) (3N + 1)] summation
• 16. Sn/Tn=3n+1/2n-1 RT please as soon as possible! Thank you~ If the sum of their first n terms is Sn / TN = 3N + 1 / 2N-1, then the ratio of the fifth term of these two sequences is? I forgot to enter the title when I was excited~
• 17. In the triangle ABC, if the angle a = 60 degrees and BC = 3, then the value range of AC + AB on both sides of the triangle ABC?
• 18. In the triangle ABC, if B = 2, angle B = 45 °, if the triangle has two solutions, find the value range of A The answer I got was 0 to 2 root 2, 2 to 2 root 2 The sine theorem of triangle is applied ~ (in triangle ABC, a / Sina = B / SINB = C / sinc)
• 19. In the triangle ABC, B = 4 and a = 2 are known. If the triangle has a solution, then the value range of ∠ A is given
• 20. It is known that in the triangle ABC, the angle B is equal to twice the angle c, and the proof of AC = AB + BD is given