a(n) is the smallest prime p such that p-1 and p+1 both have n prime factors (with multiplicity).
A154598
a(n) is the smallest prime p such that p-1 and p+1 both have n prime factors (with multiplicity).
Terms
- a(0) =5a(1) =19a(2) =89a(3) =271a(4) =1889a(5) =10529a(6) =75329a(7) =157951a(8) =3885569a(9) =11350529a(10) =98690561a(11) =65071999a(12) =652963841a(13) =6548416001a(14) =253401579521a(15) =160283668481
External references
- oeis: A154598