Least k such that k*30^n-1 , k*30^n+1, and 2*k*30^n-1 are prime; that is, twin primes and a Sophie Germain prime.
A212956
Least k such that k*30^n-1 , k*30^n+1, and 2*k*30^n-1 are prime; that is, twin primes and a Sophie Germain prime.
Terms
- a(0) =1a(1) =13a(2) =91a(3) =209a(4) =213a(5) =217a(6) =8a(7) =283a(8) =82a(9) =3150a(10) =105a(11) =3729a(12) =3548a(13) =1267a(14) =5218a(15) =3459a(16) =571a(17) =1911a(18) =12088a(19) =858a(20) =4606a(21) =3171a(22) =5305a(23) =6890a(24) =5024a(25) =19149a(26) =14766a(27) =16640a(28) =15333a(29) =39382
External references
- oeis: A212956