- 91 is composite
- 9901 is prime
- 999001is composite
- 99990001 is prime
- 9999900001 is composite
- 999999000001 is prime
- 99999990000001 is composite
- 9999999900000001 is prime
- 999999999000000001 is composite
Unfortunately, the alternating pattern doesnβt continue.

The next term in this sequence is composite again.

# The Empty Brain!

π¨π₯π

Jul
30

Jul
29

Jul
28

← Older posts
Page 1 of 245