Ada yng tw aturannya berapa???

menurut saya itu
2n + 5
bukti:
2(0) + 5 = 0 + 5 = 5
2(6) + 5 = 12 + 5 = 17
2(7) + 5 = 14 + 5 = 19
2(8) + 5 = 16 + 5 = 21
2(9) + 5 = 18 + 5 = 23