a(n) = n! * Sum_{k=0..floor(n/3)} (-1)^k / (3*k)!.
A348597
a(n) = n! * Sum_{k=0..floor(n/3)} (-1)^k / (3*k)!.
Terms
- a(0) =1a(1) =1a(2) =2a(3) =5a(4) =20a(5) =100a(6) =601a(7) =4207a(8) =33656a(9) =302903a(10) =3029030a(11) =33319330a(12) =399831961a(13) =5197815493a(14) =72769416902
External references
- oeis: A348597