I believe it is 120.
* * * * *
That is a belief which may or may not be justified.
I suggest 76, with the following justification:
Fit the polynomial t(n) = (9x4 - 82x3 + 279x2 -398x + 216)/24 for n = 1, 2, 3, etc.
Chat with our AI personalities
10
57
One number does not make a sequence (nor a series).
The number 7 comes next.
mcmlx