a(n) is the least semiprime having a(n-1) as a substring, a(1)=4.
A254718
a(n) is the least semiprime having a(n-1) as a substring, a(1)=4.
Terms
- a(0) =4a(1) =14a(2) =141a(3) =1141a(4) =11141a(5) =111413a(6) =1111413a(7) =11114137a(8) =111114137a(9) =1111141373a(10) =11111141373a(11) =111111413737
External references
- oeis: A254718