a(n) is the largest prime divisor of the number A173426(n) = concatenate(1,2,...,n-1,n,n-1,...,2,1); a(1) = 1.
A075024
a(n) is the largest prime divisor of the number A173426(n) = concatenate(1,2,...,n-1,n,n-1,...,2,1); a(1) = 1.
Terms
- a(0) =1a(1) =11a(2) =37a(3) =101a(4) =271a(5) =37a(6) =4649a(7) =137a(8) =333667
External references
- oeis: A075024