a(1) = 1, a(n) = Sum_{k=1..n-1} ((8^k - 1)/7)*a(k).
A015509
a(1) = 1, a(n) = Sum_{k=1..n-1} ((8^k - 1)/7)*a(k).
Terms
- a(0) =1a(1) =1a(2) =10a(3) =740a(4) =433640a(5) =2030302480
External references
- oeis: A015509
A015509
a(1) = 1, a(n) = Sum_{k=1..n-1} ((8^k - 1)/7)*a(k).