<Tr> <Th> Division </Th> <Th> </Th> <Th> </Th> <Th> </Th> <Th> </Th> <Th> 5 </Th> <Th> 6 </Th> <Th> 7 </Th> <Th> 8 </Th> <Th> 9 </Th> <Th> 10 </Th> <Th> </Th> <Th> 11 </Th> <Th> 12 </Th> <Th> 13 </Th> <Th> 14 </Th> <Th> 15 </Th> <Th> 16 </Th> </Tr> <Tr> <Td> 13 ÷ x </Td> <Td> 13 </Td> <Td> 6.5 </Td> <Td> 4. 3 </Td> <Td> 3.25 </Td> <Td> 2.6 </Td> <Td> 2.1 6 </Td> <Td> 1. 857142 </Td> <Td> 1.625 </Td> <Td> 1. 4 </Td> <Td> 1.3 </Td> <Th> </Th> <Td> 1. 18 </Td> <Td> 1.08 3 </Td> <Td> </Td> <Td> 0.9 285714 </Td> <Td> 0.8 6 </Td> <Td> 0.8125 </Td> </Tr> <Tr> <Td> x ÷ 13 </Td> <Td> 0. 076923 </Td> <Td> 0. 153846 </Td> <Td> 0. 230769 </Td> <Td> 0. 307692 </Td> <Td> 0. 384615 </Td> <Td> 0. 461538 </Td> <Td> 0. 538461 </Td> <Td> 0. 615384 </Td> <Td> 0. 692307 </Td> <Td> 0. 762930 </Td> <Th> </Th> <Td> 0. 846153 </Td> <Td> 0. 923076 </Td> <Td> </Td> <Td> 1. 076923 </Td> <Td> 1. 153846 </Td> <Td> 1. 230769 </Td> </Tr> <Table> <Tr> <Th> Exponentiation </Th> <Th> </Th> <Th> </Th> <Th> </Th> <Th> </Th> <Th> 5 </Th> <Th> 6 </Th> <Th> 7 </Th> <Th> 8 </Th> <Th> 9 </Th> <Th> 10 </Th> <Th> </Th> <Th> 11 </Th> <Th> 12 </Th> <Th> 13 </Th> </Tr> <Tr> <Td> 13 </Td> <Td> 13 </Td> <Td> 169 </Td> <Td> 2197 </Td> <Td> 28561 </Td> <Td> 371293 </Td> <Td> 4826809 </Td> <Td> 62748517 </Td> <Td> 815730721 </Td> <Td> 10604499373 </Td> <Td> 137858491849 </Td> <Th> </Th> <Td> 1792160394037 </Td> <Td> 23298085122481 </Td> <Td> 302875106592253 </Td> </Tr> <Tr> <Td> x </Td> <Td> </Td> <Td> 8192 </Td> <Td> 1594323 </Td> <Td> 67108864 </Td> <Td> 1220703125 </Td> <Td> 13060694016 </Td> <Td> 96889010407 </Td> <Td> 549755813888 </Td> <Td> 2541865828329 </Td> <Td> 10000000000000 </Td> <Th> </Th> <Td> 34522712143931 </Td> <Td> 106993205379072 </Td> <Td> 302875106592253 </Td> </Tr> </Table>

Where did the number 13 superstition come from