a(1) = 3, a(n) = smallest multiple of a(n-1) such that 10*a(n) + 1 is prime.
A089325
a(1) = 3, a(n) = smallest multiple of a(n-1) such that 10*a(n) + 1 is prime.
Terms
- a(0) =3a(1) =6a(2) =18a(3) =54a(4) =162a(5) =486a(6) =972a(7) =1944a(8) =5832a(9) =40824a(10) =204120a(11) =408240a(12) =816480a(13) =1632960a(14) =3265920a(15) =6531840a(16) =26127360a(17) =130636800a(18) =391910400a(19) =1175731200a(20) =14108774400a(21) =56435097600
External references
- oeis: A089325