F.6 math arithmetic sequence~

2011-09-21 2:29 am

The number of toothpicks in the 1st, 2nd, 3rd and 4th figures are 4, 12, 24 and 40 respectively. Find the number of toothpicks in the n th figure.

回答 (1)

2011-09-21 2:35 am

✔ 最佳答案

= 4 * ((1 + n) * n) / 2

By the way I do not think this is an arithematic sequence.

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