-1 + Sum (k-1)! C(n,k), k = 1..n for n > 0, a(0) = 1.

A001338

-1 + Sum (k-1)! C(n,k), k = 1..n for n > 0, a(0) = 1.

Terms

    a(0) =1a(1) =0a(2) =2a(3) =7a(4) =23a(5) =88a(6) =414a(7) =2371a(8) =16071a(9) =125672a(10) =1112082a(11) =10976183a(12) =119481295a(13) =1421542640a(14) =18348340126a(15) =255323504931

External references