There are not enough numbers to be certain.
The rule for the nth term could be
Subtract 6 from the previous term giving 30, 24, 18, etc
or
Multiply previous term by 0.8 giving 30, 24, 21.6, etc
etc
81
75. The sequence is:- multiply by three, divide by two, add one.
The next is 3.
It is impossible to say what sequence comes after the given set of numbers. What I can do is to suggest what number might come next in the given sequence.Using the ruleUn = (7n5 - 129n4 + 891n3 - 2859n2 + 4298n - 1488)/24 for n = 1, 2, 3, ...the next number is 85.
68
81
The next number in the sequence is 48.
16
Think it's 30...then 20
75. The sequence is:- multiply by three, divide by two, add one.
The next is 3.
182.25. 16 is square of 4, 36 is a square of 6, 81 is a square of 9. So the next term will be a squre.24=46, 54=69, therefore 121.5=9*x, then you will get x=13.5 and square of 13.5= 182.25 thats all
20
It is impossible to say what sequence comes after the given set of numbers. What I can do is to suggest what number might come next in the given sequence.Using the ruleUn = (7n5 - 129n4 + 891n3 - 2859n2 + 4298n - 1488)/24 for n = 1, 2, 3, ...the next number is 85.
There appears to be a number missing in the sequence - as the difference of the differences is equal to 12 each time, apart from between 221 and 323, where the difference is 24.
612
68