A286951 Irregular triangle read by rows: T(n,k) is the number of simple graphs with n vertices with matching number k (0 <= k <= floor(n/2)).

1, 1, 1, 1, 1, 3, 1, 4, 6, 1, 5, 28, 1, 6, 48, 101, 1, 7, 73, 963, 1, 8, 106, 1818, 10413, 1, 9, 147, 3383, 271128, 1, 10, 198, 6129, 441031, 11557799

Offset: 0

Author

Eric W. Weisstein, May 17 2017

Keywords

• nonn
• tabf

Examples

			Triangle begins:
  1;
  1;
  1, 1;
  1, 3;
  1, 4,  6;
  1, 5,  28;
  1, 6,  48,  101;
  1, 7,  73,  963;
  1, 8, 106, 1818, 10413;
  ...
		

Links

• Eric Weisstein's World of Mathematics, Matching Number

Crossrefs

Row sums are A000088.

T(2n,n) gives A218462 (for n>0).

Extensions

Name corrected by Andrew Howroyd, Nov 04 2017

T(0,0)=1 added by Alois P. Heinz, Nov 04 2017