Palindromic Merlon Primes - Program Outputs

8*(10⁷-1)/9 + 10⁶ + 10³ + 1

Using Pari/gp (< 1s)
     gp > isprime(8*(10^7-1)/9+10^6+10^3+1)
     %1 = 1

8*(10¹¹-1)/9 + 10¹⁰ + 10⁵ + 1

Using Pari/gp (< 1s)
     gp > isprime(8*(10^11-1)/9+10^10+10^5+1)
     %1 = 1

8*(10¹⁹-1)/9 + 10¹⁸ + 10⁹ + 1

Using Pari/gp (< 1s)
     gp > isprime(8*(10^19-1)/9+10^18+10^9+1)
     %1 = 1

8*(10³¹-1)/9 + 10³⁰ + 10¹⁵ + 1

Using Pari/gp (< 1s)
     gp > isprime(8*(10^31-1)/9+10^30+10^15+1)
     %1 = 1

8*(10⁶⁷-1)/9 + 10⁶⁶ + 10³³ + 1

Using Pari/gp (< 1s)
     gp > isprime(8*(10^67-1)/9+10^66+10^33+1)
     %1 = 1

8*(10¹¹⁵-1)/9 + 10¹¹⁴ + 10⁵⁷ + 1

Using Pari/gp (< 1s)
     gp > isprime(8*(10^115-1)/9+10^114+10^57+1)
     %1 = 1

8*(10⁷⁶⁷-1)/9 + 10⁷⁶⁶ + 10³⁸³ + 1

Using Pari/gp (time = 30,203 ms)
     gp > default(parisizemax,"1G")
     gp > isprime(8*(10^767-1)/9+10^766+10^383+1)
     %1 = 1

Patrick De Geest - Belgium