889 859 834 814

Take successive differences

-30, -25, -20

Continue successive differences using the pattern:

-30, -25, -20, -15, -10, -5, 0, 5, 10, 15, 20

Adding the successive differences:

889, 859, 834, 814, 799, 789, 784, 784, 789, 799, 814 

Since the differences are constants, its a quadratic
form



Edwin