Number of 2-diregular digraphs with n nodes.
A005641
Number of 2-diregular digraphs with n nodes.
Terms
- a(0) =1a(1) =3a(2) =8a(3) =27a(4) =131a(5) =711a(6) =5055a(7) =41607a(8) =389759a(9) =4065605a(10) =46612528a(11) =581713045a(12) =7846380548a(13) =113718755478
External references
- oeis: A005641