a(n) = A053141(n)*A001109(n+1) = Sum_{k=A053141(n)+1..A001109(n+1)-1} k.

A175322

a(n) = A053141(n)*A001109(n+1) = Sum_{k=A053141(n)+1..A001109(n+1)-1} k.

Terms

    a(0) =12a(1) =490a(2) =17136a(3) =584988a(4) =19889100a(5) =675741430a(6) =22955884992a(7) =779827644120

External references