If b(n) is A011900(n) and c(n) is A001109(n), then a(n) = b(n)*c(n) = b(n) + (b(n)+1) + (b(n)+2) + ... + c(n).

A011906

If b(n) is A011900(n) and c(n) is A001109(n), then a(n) = b(n)*c(n) = b(n) + (b(n)+1) + (b(n)+2) + ... + c(n).

Terms

    a(0) =1a(1) =18a(2) =525a(3) =17340a(4) =586177a(5) =19896030a(6) =675781821a(7) =22956120408a(8) =779829016225

External references