a(0) = 0; thereafter, a(n) = (2*n-1)*a(n-1) + 1.

A286286

a(0) = 0; thereafter, a(n) = (2*n-1)*a(n-1) + 1.

Terms

    a(0) =0a(1) =1a(2) =4a(3) =21a(4) =148a(5) =1333a(6) =14664a(7) =190633a(8) =2859496a(9) =48611433a(10) =923617228a(11) =19395961789a(12) =446107121148

External references