a(0) = 1; a(n) = Sum_{k=1..n} binomial(n,k) * k!! * a(n-k).
A335848
a(0) = 1; a(n) = Sum_{k=1..n} binomial(n,k) * k!! * a(n-k).
Terms
- a(0) =1a(1) =1a(2) =4a(3) =21a(4) =152a(5) =1355a(6) =14568a(7) =182427a(8) =2612224a(9) =42073209a(10) =752981280a(11) =14823367845a(12) =318347145216
External references
- oeis: A335848