Given any number it is easy to find a rule based on a polynomial of order 7 such that the first seven numbers are as listed in the question and the eighth is the given number. That is, it is easy to find a rule so that any number can be the "next" in the sequence.
The polynomial of order six that fits is
Un = (n6 - 15n5 + 115n4 - 405n3 + 964n2 - 660n + 240)/240 and
accordingly, U8 = 379.
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They are: 0, -5, -10
1, 2, 5, 10, 19, 38, 95, 190.
1 x 190, 2 x 95, 5 x 38, 10 x 19
280
30, 42, 38