from fractions import Fraction
value, difference, second_difference = 2, 3, 2
c = value
a = Fraction(second_difference, 2)
b = Fraction(difference) - a
values = []
for n in range(1, 11):
    value += difference
    values.append(value)
    difference += second_difference
assert values[:2] == [5, 10]
result = {"coefficients": [str(a), str(b), str(c)], "f10": str(values[-1]),
          "sum_1_to_10": str(sum(values))}
import json
print(json.dumps(result, ensure_ascii=False, sort_keys=True))