a(1)=1; for n >1 a(n) is the smallest prime divisor of the number obtained from concatenation of 1 and the first n-1 composites.
A241845
a(1)=1; for n >1 a(n) is the smallest prime divisor of the number obtained from concatenation of 1 and the first n-1 composites.
Terms
- a(0) =1a(1) =2a(2) =2a(3) =2a(4) =37a(5) =2a(6) =2a(7) =2a(8) =5a(9) =2a(10) =2a(11) =2a(12) =27793a(13) =2a(14) =2a(15) =3a(16) =2a(17) =29a(18) =2a(19) =2a(20) =2a(21) =19a(22) =2a(23) =5a(24) =2a(25) =2a(27) =2a(28) =2a(29) =2a(30) =5
External references
- oeis: A241845