2 problems

Wu's divisibility-by-3 conjecture for appended-digit primes
Wu's divisibility-by-3 conjecture. If $c(n)=0$ , then $n$ is divisible by $3$ .
opendigit-concatenation number-theory primality
0 responses
04
The OEIS A256480 conjecture for prepended-digit primes
OEIS A256480 conjecture.
opendigit-concatenation number-theory primality
0 responses
03