a(n) = f(n,n) where f(0,n) = f(n,0) = n! and f(m,n) = f(m-1,n) + f(m,n-1) + f(m-1,n-1).
A346374
a(n) = f(n,n) where f(0,n) = f(n,0) = n! and f(m,n) = f(m-1,n) + f(m,n-1) + f(m-1,n-1).
Terms
- a(0) =1a(1) =3a(2) =15a(3) =85a(4) =511a(5) =3221a(6) =21339a(7) =149969a(8) =1133215a(9) =9343525a(10) =85089883a(11) =860979329a(12) =9665236335a(13) =119534610885
External references
- oeis: A346374