What is the number of terms of the sequence 1 + 3 + 5 +. + (2n-1)? How to calculate it?

RELATED INFORMATIONS

• 1. If 2 and 8 / 21 divided by M = 2 and 1 / 2, then m * 7 / 20=____
• 2. Given that n is a positive integer and (xn) 2 = 9, find the value of (13x3n) 2-3 (x2) 2n
• 3. Given that n is a positive integer and (xn) 2 = 9, find the value of (13x3n) 2-3 (x2) 2n
• 4. 111…… 1155…… 56 is a perfect square
• 5. If n is an integer, try to explain that (2n + 1) ^ 2 - (2n-1) ^ 2 is a multiple of 8, and write the conclusion in one sentence
• 6. Is the square of any odd number minus 1 a multiple of 8,
• 7. The square of any odd number minus 1 is a multiple of 8. Why?
• 8. It is proved that when n is an integer, the square of the square difference (2n + 1) of two consecutive odd numbers is a multiple of 8
• 9. Calculate (square of x-2x + 1-y) / (x + y + 1)
• 10. Calculate the square of (X-Y) - 2x (X-Y)
• 11. How to find the number of items in a sequence? For example, how to find the number of items in a sequence an = (2n + 1) + (2n-1) + (2n-2) +. + 7 + 5 + 1 There is also a general way to find the number of items in a sequence I'm in the third year of senior high school now. I'm going through the first round of review to find out how to learn
• 12. The number of terms of sequence 3,5,9,11..., 2n + 1
• 13. The number of items of 9.11.13.2n-1 is 1. The number of items of 9.11.13... 2N-1 is
• 14. The number of terms of sequence 5,7,9,11,..., 2N-1 is
• 15. Find sequence 3 / 1 * (2 ^ 2), 5 / (2 ^ 2) * (3 ^ 2), 7 / (3 ^ 2) * (4 ^ 2) The sum of the first n terms of (2n + 1) / A ^ 2 (n + 1) ^ 2
• 16. 3,11,43171683... Is there an analytic expression for this sequence? Wrong. It's the general formula!
• 17. The combination of interval sequence and equal difference equal ratio mixed sequence, such as: 3,1,5,1,11,1,21,1, (43) How to solve it?
• 18. The law of exploration: 1,3,5,11,21, (), (), 171341
• 19. 1. What is the general term formula for 3; 5; 11; 21; 43; 85; 171?
• 20. Sequence √ 3, 3, √ 15 ,√3（2n-1),…… What is 9?