Computing 'Weakly Primes'A digitally delicate (or weakly prime) number is a prime number that becomes composite if any one of its digits is replaced by any other digit. Essentially, it is a prime that is "surrounded" by composite numbers in the digital space
Code:
podman run --rm --platform linux/arm64 --network=slirp4netns -it n4jm4/raspberry-pi-os bashCode:
apt update apt install nano pari-gp fastfetch nano wp.gp gp<wp.gp gp -q < wp.gp > results.txt &Code:
is_weakly_prime(p) = { my(s = digits(p), len = #s, original_digit, test_n); \\ Iterate through each digit position for(i = 1, len, original_digit = s[i]; \\ Replace with every possible digit 0-9 for(d = 0, 9, if(d == original_digit, next); \\ Skip the original digit if(i == 1 && d == 0, next); \\ Skip leading zeros \\ Construct the new number s[i] = d; test_n = fromdigits(s); \\ If any variation is prime, p is NOT weakly prime if(isprime(test_n), s[i] = original_digit; \\ Reset before returning return(0) ); ); s[i] = original_digit; \\ Reset digit for next position ); return(1);}get_weakly_primes(n) = { my(primes_list = listcreate()); forprime(p = 2, n, if(is_weakly_prime(p), listput(primes_list, p)) ); return(primes_list);}Statistics: Posted by geev03 — Sat Feb 21, 2026 10:35 pm