What's the rule of 5 4 12 17.5 24 sequence! Find the last five numbers. Find the average of the last 10 numbers I don't know the rules of these five numbers!

What's the rule of 5 4 12 17.5 24 sequence! Find the last five numbers. Find the average of the last 10 numbers I don't know the rules of these five numbers!

Well, let's divide each number by 0.5 to get 3 8 24 25 48. From observation, we can find that 3 = 2 * 2-1 8 = 3 * 3-1 24 = 5 * 5-1 35 = 6 * 6-1 48 = 7 * 7-1, so we say that 15 = 4 * 4-1 is missing, that is to say, there is a 7.5 missing between 4 and 12 in the 5 numbers 1.5 4 12 17.5 24, so these numbers should be 0.5 * 3 0.5 * 8 0.5 * 15 0.5 * 24 0.5 * 35 0.5 * 48 0.5 * 63 0.5 * 80 0.5 * 99 0.5 * 120 0.5 * 143, and so on It's all 0.5 times the square of a number and then minus one to get the remaining number, and then average it