Let the sum of the first n terms of the sequence {an} be Sn = n square-4n + 1, and find the general term formula

an=Sn-Sn-1=2n-5 (n>=2)
a1=S1=-2

RELATED INFORMATIONS

1. In the sequence {an}, A1 = 1 / 2, an + 1 = an = 1 / (4N ^ 2-1), find the general term formula of {an}
2. Given that the sequence {an} satisfies A1 = 1, (2n + 5) (an + 1) - (2n + 7) an = 4N ^ 2 + 24N + 35 (n ∈ n +), then the general term formula of sequence an is?
3. Let the sum of the first n terms be Sn, then S100=
4. The general term formula of sequence {an} is an = (- 1) ^ (n-1) * (4n-3), and the sum of the first n terms of sequence {an} can be obtained Solution: when n is even, Sn = (1-5) + (9-13) + (17-21) + ·· + [(- 1) ^ (n-2) (4n-7) + (- 1) ^ (n-1) (4n-3)] = - 4 * (n / 2) = - 2n When n is an odd number Why do you do this? I don't understand. Can you explain it? Thank you I still don't understand
5. If the general term formula of sequence an is known as an = 4N + 1, then the first n terms and Sn are equal to
6. Let the general term formula of arithmetic sequence {an} be 3n-2, and find the sum formula of its first n terms
7. (1) Let the general term formula of arithmetic sequence {an} be 3n-2, and find the sum formula of its first n terms
8. In the arithmetic sequence {an}, A1 = - 60, A17 = - 12. (1) find the general term an, (2) find the sum of the first 30 terms of the sequence
9. In the known arithmetic sequence {an}, D ＞ 0, a3a7 = - 16, A2 + A8 = 0, let TN = | A1 | + | A2 | + +|An |. Find the general formula an of (I) {an}; (II) find TN
10. In the known arithmetic sequence {an}, a3a7 = - 16, A4 + A6 = 0, ① find {an} ② if D
11. It is known that the sum of the first n terms of the sequence an is Sn, and an + 2Sn = 4N (n ∈ n +). 1) to find the general term formula 2 of the sequence an It is known that the sum of the first n terms of an is Sn, and an + 2Sn = 4N (n ∈ n +) 1) The general term formula of the sequence an 2) If BN = Nan, find the first n terms of BN and TN
12. If the sum of the preceding terms of sequence an is Sn = 4N ^ 2-N + 2, then the general term formula is
13. (2 / 3) on the straight line X-Y + 2 = 0, find the general term formula of the sequence {an} {BN}. The second question: let CN = anbn, find the first n terms and TN of the sequence {CN}, and (2 / 3) on the straight line X-Y + 2 = 0, find the general term formula of the sequence {an} {BN}. The second question: let CN = anbn, find the first n terms and TN of the sequence {CN}, and satisfy TN
14. A1 = 3, an + 1-an = 0, the general term formula of sequence BN satisfies anbn = - 1 ^ n Ask BN =?
15. If the inequality ax ^ 2-6x + A ^ 2 about X
16. If the solution set of X inequality ax + b > 0 is (1, infinity), then the solution set of X inequality (AX + b) (X-2) > 0
17. If the solution set of inequality ax > b about X is (1, positive infinity), then the solution set of inequality (ax-b) / X-2 > 0 about X is (1, positive infinity) The answer is less than negative 1, greater than 2. Why is a greater than zero? If B is negative, it's OK
18. How much is infinitesimal multiplied by infinity
19. What is infinity multiplied by infinity? What is infinitesimal multiplied by infinitesimal? What is infinity plus infinitesimal?
20. Is infinitesimal divided by infinity or infinitesimal?