a(n) = [x^n] 1/(1 - x)^(n*(n-1)/2).

A386879

a(n) = [x^n] 1/(1 - x)^(n*(n-1)/2).

Terms

    a(0) =1a(1) =0a(2) =1a(3) =10a(4) =126a(5) =2002a(6) =38760a(7) =888030a(8) =23535820a(9) =708930508a(10) =23930713170a(11) =895068996640

External references