Number of 2-diregular connected digraphs with n nodes.
A005642
Number of 2-diregular connected digraphs with n nodes.
Terms
- a(0) =1a(1) =3a(2) =7a(3) =24a(4) =117a(5) =663a(6) =4824a(7) =40367a(8) =381554a(9) =4001849a(10) =46043780a(11) =576018785a(12) =7783281188a(13) =112953364381
External references
- oeis: A005642