Sixteen sequences of primes obtained by concatenation from p-1 respectively p+1 where p prime

In this paper I make the following four conjectures: (I) there exist, for any prime p having the value of the last digit d equal to 1, respectively to 3, 7 or 9, an infinity of primes obtained concatenating p – 1 with the value of d; (II) there exist, for any prime p having the value of the last digit d equal to 1, respectively to 3, 7 or 9, an infinity of primes obtained concatenating twice p – 1 with the value of d; (III) there exist, for any prime p having the value of the last digit d equal to 1, respectively to 3, 7 or 9, an infinity of primes obtained concatenating p + 1 with the value of d; (II) there exist, for any prime p having the value of the last digit d equal to 1, respectively to 3, 7 or 9, an infinity of primes obtained concatenating twice p + 1 with the value of d.