If the general term formula of sequence an is an = ncosn π / 2 + 1 and the sum of the first n terms is Sn, then s2012 =

This is a typical periodic sequence summation problem, the period is 4, the following 1 separately summation of 2012, and then calculate the previous periodic sequence

RELATED INFORMATIONS

1. The general term formula of sequence {an} is an = ncosn π 2 + 1, the sum of the first n terms is Sn, then s2012=______ ．
2. Let the first n terms of sequence {an} and Sn = N2, then A8=______ ．
3. The general term of sequence {an} is an = n & # 178; (COS & # 178; n π / 3-sin & # 178; n π / 3), and the sum of the first n terms is SN (1) Find SN; (2) Let BN = s (3n) / (n · 4N), find the first n terms and TN of the sequence {BN}
4. If the general term of sequence {a n} a n = n & # 178; (COS & # 178; n π / 3-sin & # 178; n π / 3), the sum of the first n terms is Sn, then S30 is?
5. If the general term an of sequence {an} is n ^ 2 {cos ^ (n * 180) / 3-sin ^ (n * 180) / 3}, and the sum of the first n terms is Sn, then S30 is?
6. If the sum of the first n terms of the sequence an is Sn, then S30 =?
7. If the sum of the first n terms of the sequence an is Sn, then Sn =?
8. In the sequence {an}, if an = n (sin n π / 2 + cos n π / 2), the sum of the first n terms is Sn, then S100 =?
9. Let the sum of the first n terms of a sequence an be Sn, the N + 1st power of A1 = 1 Na = (n + 2) Sn (n belongs to n-positive) prove that the sequence Sn / N is an equal ratio sequence and find Sn if the sequence Let the sum of the first n terms of the sequence an be SN. Given that A1 = 1, the nth + 1st power of Na = (n + 2) Sn (n belongs to n positive), prove that the sequence Sn / N is an equal ratio sequence and find SN. If the sum of the first n terms of the sequence SN is TN, find TN should be explained in detail
10. Given the first n terms of sequence {an} and Sn = n ^ 2 + N + 1, is an arithmetic sequence?
11. If the general term formula of sequence {an} is an = n ^ 2cosn π and Sn is the sum of its first n terms, then (s2012) / 2013 is obtained Hurry up. It's urgent
12. We know the arithmetic sequence {an} A1 = 25, S17 = S9; The known arithmetic sequence {an} A1 = 25, S17 = S9 \X05 (1) the general formula of {an}; \x05(2)S1、S2、… Which one is the largest? And find the maximum
13. In the arithmetic sequence {an}, A1 = 25, S17 = S9, find the general term formula of {an} (important process)
14. In the arithmetic sequence {an}, A1 = 25, S9 = S17, then______ Item and maximum
15. In the arithmetic sequence {an}, A1 = 25, S9 = S17, then______ Item and maximum
16. In the arithmetic sequence {an}, A1 = 22, S17 = S9, find the maximum value of Sn
17. In the arithmetic sequence {an}, it is known that A1 > 0, Sn is the sum of the first n terms of the sequence, if S9 > 0, S10
18. In the arithmetic sequence, when A1 is greater than 0.s9 = S17 and N is equal to, Sn has the maximum value/
19. In the arithmetic sequence {an}, Sn is the sum of the first n terms of {an}, A1 = 25, S17 = S9, find the maximum value of Sn
20. In the arithmetic sequence {an}, if A1 ＜ 0, S9 = S12, then n is equal to___ The minimum value of Sn is obtained