Number of connected regular simple graphs on n vertices with girth exactly 4.
A186744
Number of connected regular simple graphs on n vertices with girth exactly 4.
Terms
- a(0) =0a(1) =0a(2) =0a(3) =0a(4) =1a(5) =0a(6) =1a(7) =0a(8) =3a(9) =0a(10) =8a(11) =2a(12) =34a(13) =31a(14) =330a(15) =1607a(16) =17970a(17) =193906a(18) =2867269a(19) =32674056a(20) =1581626328a(21) =6705889815
External references
- oeis: A186744