a(n) = (2*n-1)!! * Sum_{k=1..n} (-1)^(k-1)/(2*k-1)!!.
A368794
a(n) = (2*n-1)!! * Sum_{k=1..n} (-1)^(k-1)/(2*k-1)!!.
Terms
- a(0) =0a(1) =1a(2) =2a(3) =11a(4) =76a(5) =685a(6) =7534a(7) =97943a(8) =1469144a(9) =24975449a(10) =474533530a(11) =9965204131a(12) =229199695012
External references
- oeis: A368794