My book shows following sequence:

9, 10, 8, 13, 5, 18, 0, 6, 12, 15, 3, 7, 11, 1, 17, 16, 2, 14, 4

I am trying to regenerate it. I am able to find:

h(k) = 9%19 = 9

h(k) + 1 power 2 = 10 % 19 = 10

h(k) - 1 power 2 = 8 % 19 = 8

h(k) + 2 power 2 = 13 % 19 = 13

h(k) - 2 power 2 = 5 % 19 = 5

h(k) + 3 power 2 = 18 % 19 = 18

h(k) - 3 power 2 = 0

h(k) + 4 power 2 = 9 + 16 = 25 % 19 = 6

h(k) - 4 power 2 = 9 -16 = -7 %19 = -7 which is wrong, it should be 12. I know 19 -7 = 12. But i dont know how to get it.

They are using the formula:

h(K), h(K) + 1, h(k) -1, h(k) + 4, h(K) - 4, .... h(K) + (TSIZE -1)power 2 / 4, h(k) - (TSIZE -1) power 2 /4 all divided modulo TSize.

where j =4 & table size = 19 & assuming h(K) = 9.

Some body please guide me how to solve it.

Zulfi.