a(n) = [x^n] Product_{k=1..n} (k + x + k*x^2), for n >= 0.

A322238

a(n) = [x^n] Product_{k=1..n} (k + x + k*x^2), for n >= 0.

Terms

    a(0) =1a(1) =1a(2) =5a(3) =23a(4) =215a(5) =1815a(6) =24495a(7) =302619a(8) =5320667a(9) =86715299a(10) =1876495799a(11) =38014052089a(12) =976259270857

External references