a(n) is the least x such that x-1 and x+1 are prime and there are exactly n primes of the form x-1+t or x+1+t where t divides x.
A340170
a(n) is the least x such that x-1 and x+1 are prime and there are exactly n primes of the form x-1+t or x+1+t where t divides x.
Terms
- a(0) =1698a(1) =4a(2) =6a(3) =12a(4) =30a(5) =60a(6) =72a(7) =192a(8) =240a(9) =1428a(10) =180a(11) =420a(12) =432a(13) =2592a(14) =2268a(15) =2340a(16) =2688a(17) =15288a(18) =3360a(19) =9000a(20) =46440a(21) =9720a(22) =6300a(23) =6552a(24) =53550a(25) =23040a(26) =16632a(27) =7560a(28) =21600a(29) =13680
External references
- oeis: A340170