@aminooo: > Yeah devo, you're supposed to post something. > I'll post this one: > > 4,16,37,58,89,145,42,20 > > search well :) Sum of the square of each previous digit, 4 16 37 ( 4 ) ( 1 6 ) ( 3 7 ) 4^2 = 16, 1^2 + 6^2 = 37, 3^2 + 7^2 = 58, etc An interesting thing to note is that if you continue with the sequence it repeats itself after 20. –----------------------------------------------------------------------------------------- Geometric thinking: Why does this work? (Works for all squares). **4^2** = 16; 16 + 4 + 5 = 25 = **5^2.** **13^2** = 169; 169 + 13 + 14 = 196 = **14^2.** **14^2** = 196; 196 + 14 + 15 + 15 + 16 = 256 = **16^2.**
