There is a column of numbers: 3.6.9.12 ····· what is the number 200 in this column? What is the sum of the top 100 numbers?

Because it's 3,6,9,12, so it's an arithmetic sequence, the tolerance is 3, the formula is 3N, the first number n = 1, the second number n = 2, so the 200th number is 600
The sum of the first 100 numbers is: (a1 + A100) * 100 / 2 = 15150
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