What Number Completes This Sequence 3 9 4 5 25 20 21 441 Is?

Pattern is ^2, then -5, then +1, then it repeats.

Start = (3)

3^2 = (9)

9-5= (4)

4+1 = (5)

5^2 = (25)

25-5 = (20)

20+1 = (21)

21^2= (441)

441-5 = (436)

436+1 = (437)

437^2 = (190,969)

190969-5= (190,964)

190964+1 = (190,965)

190965^2= (36,467,631,225)

yeah, I'm not going any further.