a(n) = sigma(10^n - 1), where sigma(n) is the sum of positive divisors of n.
A102146
a(n) = sigma(10^n - 1), where sigma(n) is the sum of positive divisors of n.
Terms
- a(0) =13a(1) =156a(2) =1520a(3) =15912a(4) =148512a(5) =2042880a(6) =14508000a(7) =162493344a(8) =1534205464a(9) =16203253248a(10) =144451398000
External references
- oeis: A102146