a(0) = 13; for n > 0, a(n) is the greatest prime factor of PreviousPrime(a(n-1))*a(n-1)-1 where PreviousPrime(prime(k))=prime(k-1).

A031442

a(0) = 13; for n > 0, a(n) is the greatest prime factor of PreviousPrime(a(n-1))*a(n-1)-1 where PreviousPrime(prime(k))=prime(k-1).

Terms

    a(0) =13a(1) =71a(2) =41a(3) =379a(4) =23561a(5) =5431a(6) =20269a(7) =89a(8) =1231a(9) =44497a(10) =329952671a(11) =36583a(12) =1126159a(13) =90209117a(14) =14095897a(15) =15272393a(16) =13887359a(17) =256460794943

External references