A185205 Triangular array D(n,k) counting disconnected k-regular simple graphs on n vertices with girth at least 5.
0, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 1, 0, 1, 1, 1, 2, 1, 0, 2, 1, 1, 3, 1, 0, 4, 1, 1, 5, 1, 0, 6, 1, 1, 8, 1, 0, 9, 1, 1, 12, 1, 1, 0, 14, 0, 1, 1, 17, 2, 1, 0, 20, 0, 1, 1, 25, 12, 1, 0, 29, 0, 1, 1, 35, 67, 1, 0, 41, 0, 1, 1, 49, 598, 1, 0
Offset: 1
Examples
0; 1; 1; 1, 1; 1, 0; 1, 1; 1, 0; 1, 1; 1, 0; 1, 1, 1; 1, 0, 1; 1, 1, 2; 1, 0, 2; 1, 1, 3; 1, 0, 4; 1, 1, 5; 1, 0, 6; 1, 1, 8; 1, 0, 9; 1, 1, 12, 1; 1, 0, 14, 0; 1, 1, 17, 2; 1, 0, 20, 0; 1, 1, 25, 12; 1, 0, 29, 0; 1, 1, 35, 67; 1, 0, 41, 0; 1, 1, 49, 598; 1, 0, 57, 0; 1, 1, 69, 7135; 1, 0, 79, 0; 1, 1, 94, 107826; 1, 0, 109, 0; 1, 1, 128, 1876709; 1, 0, 149, 0; 1, 1, 175, 35925162; 1, 0, 201, 0; 1, 1, 235, 741413221, 1; 1, 0, 271, 0, 2; 1, 1, 316, 16356258309, 11; 1, 0, 363, 0, 147; 1, 1, 422, 383936219233, 4215; 1, 0, 483, 0, 132741;
Links
- Jason Kimberley, Table of i, a(i)=D(n,k) for i = 1..147 (n = 1..43)
- Jason Kimberley, Disconnected regular graphs with girth at least 5
- Jason Kimberley, Index of sequences counting disconnected k-regular simple graphs with girth at least g