A185340 Irregular triangle E(n,g) counting not necessarily connected 4-regular simple graphs on n vertices with girth at least g.

1, 1, 2, 6, 1, 16, 0, 60, 2, 266, 2, 1547, 12, 10786, 31, 88193, 220, 805579, 1606, 8037796, 16829, 86223660, 193900, 985883873, 2452820, 11946592242, 32670332, 1, 152808993767, 456028489, 2, 2056701139136, 6636066134, 8, 28566369866514, 100135577994, 131

Offset: 5

Author

Jason Kimberley, Jan 02 2013

Keywords

• nonn
• hard
• tabf

Comments

The first column is for girth at least 3. The row length is incremented to g-2 when n reaches A037233(g).

Examples

			1;
1;
2;
6, 1;
16, 0;
60, 2;
266, 2;
1547, 12;
10786, 31;
88193, 220;
805579, 1606;
8037796, 16829;
86223660, 193900;
985883873, 2452820;
11946592242, 32670332, 1;
152808993767, 456028489, 2;
2056701139136, 6636066134, 8;
28566369866514, 100135577994, 131;
		

Links

• Jason Kimberley, Index of sequences counting not necessarily connected k-regular simple graphs with girth at least g