a(n) = n! * Sum_{k=0..floor((n-1)/3)} 1 / (3*k+1)!.
A349088
a(n) = n! * Sum_{k=0..floor((n-1)/3)} 1 / (3*k+1)!.
Terms
- a(0) =0a(1) =1a(2) =2a(3) =6a(4) =25a(5) =125a(6) =750a(7) =5251a(8) =42008a(9) =378072a(10) =3780721a(11) =41587931a(12) =499055172a(13) =6487717237a(14) =90828041318
External references
- oeis: A349088