De Bruijn's S(3,n): (3n)!/(n!)^3.
A006480
De Bruijn's S(3,n): (3n)!/(n!)^3.
Terms
- a(0) =1a(1) =6a(2) =90a(3) =1680a(4) =34650a(5) =756756a(6) =17153136a(7) =399072960a(8) =9465511770a(9) =227873431500
External references
- oeis: A006480
A006480
De Bruijn's S(3,n): (3n)!/(n!)^3.