a(n) is the numerator of Sum_{i=1..n} i!/(i^2).
A121565
a(n) is the numerator of Sum_{i=1..n} i!/(i^2).
Terms
- a(0) =0a(1) =1a(2) =3a(3) =13a(4) =11a(5) =127a(6) =427a(7) =13789a(8) =79939a(9) =550339a(10) =4360579a(11) =428990369a(12) =4270982369a(13) =608769618797
External references
- oeis: A121565