A210718 Number of disconnected regular simple graphs on n vertices with girth exactly 8.

0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 7, 7, 9, 10, 12, 13, 16, 17, 21, 23, 27, 30, 36, 39, 46, 51, 60, 66, 77, 85, 99, 110, 126, 140, 162, 179, 205, 228, 261, 289, 329, 365, 416, 461, 524, 579, 669, 726, 976, 909, 5378, 1134

Offset: 0

Author

Jason Kimberley, Dec 19 2012

Keywords

• nonn
• hard

Links

• Jason Kimberley, Table of n, a(n) for n = 0..77
• Jason Kimberley, Index of sequences counting disconnected k-regular simple graphs with girth exactly g

Formula

a(n) = A185218(n) - A185219(n).