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I'm sorry if this sounds dumb its just been bothering me and if you know anything about this please tell me because I have a lot of questions about this. (and I also apologize in advance if I used some terminologies incorrectly I'm not knowledgeable about this topic) :)

So I have been thinking about this sequence. I am really bad at explaining so I hope you understand the computation it basically goes like this Multiplication table of 2

If you add the digits of the numbers together to get a single digit integer it repeats a pattern of 2, 4, 6 , 8, 1, 3, 5, 7, 9. I have only calculated up to the number 38 but I'm sure the pattern will stay the same. But it is not only the number 2 every single number from 1-9 has its own pattern 1 follows 1, 2, 3, 4, 5, 6, 7, 8, 9 3 follows 3, 6, 9 4 follows 4, 8, 3, 7, 2, 6, 1, 5, 9 5 follows 5, 1, 6, 2, 7, 3, 8, 4, 9 6 follows 6, 3, 9 7 follows 7, 5, 3, 1, 8, 6, 4, 2, 9 8 follows 8, 7, 6, 5, 4, 3, 2, 1 9 follows 9 (I'm pretty sure this is somewhat connected to the divisibility rule) I also observed that if a number (doesn't matter how many digits) if added to make a single digit it follows the same pattern. Ex. The table of 643 643 x 1= [643] 6+4+3= 10+3= [13] 1+3= 4 Since 4 appears it will most likely follow the pattern of for but just to be sure here is the complete table of 643 643(2)= [1,286] 1+2+8+6= [17] 1+7=8 (3)=[1,929] 1+9+2+9= [21] 2+1=3 (4)=[2,572] 2+5+7+2= [16] 1+6=7 (5)=[3,215] 3+2+1+5= [11] 1+1= 2 (6)=[3,858] 3+8+5+8=[24] 2+4=6 (7)= [4.501] 4+5+1=[10] 1+0=1 (8)= [5,144] 5+1+4+4=[14] 1+4=5 (9)= [5,787] 5+7+8+7= [27] 2+7=9