One possible answer is
0.022222 x6 - 0.533333 x5 + 4.638888 x4 - 17.333333 x3 + 23.838888 x2 - 2.366666 x - 11.
In that case, the next term would be 9.
2 5 9 10 13 17 19
2 9 5 13 10 19 17
that best completes the sequence 2 9 5 13 10 19 17 is 27.
18
The number after 17 is 27. 2+7 = 9 9 - 4 = 5 5 + 8 = 13 13 - 3 = 10 10 + 9 = 19 19 - 2 = 17 17 + 10 = 27
The next number in the sequence is 27.
twenty-seven.
27
27
27
One.
27