Number of (unlabeled) loopless multigraphs with no isolated vertices such that the sum of the numbers of vertices and edges is n.
A265580
Number of (unlabeled) loopless multigraphs with no isolated vertices such that the sum of the numbers of vertices and edges is n.
Terms
- a(0) =1a(1) =0a(2) =0a(3) =1a(4) =1a(5) =2a(6) =4a(7) =7a(8) =13a(9) =27a(10) =54a(11) =112a(12) =243a(13) =538a(14) =1223a(15) =2875a(16) =6909a(17) =17052a(18) =43138a(19) =111686a(20) =295658a(21) =799684a(22) =2207356a(23) =6213391a(24) =17820961a(25) =52042771a(26) =154640528a(27) =467254731a(28) =1434837672a(29) =4475520062
External references
- oeis: A265580