Number of connected graphs with loops (symmetric relations) on n unlabeled vertices with at most n edges.

A369289

Number of connected graphs with loops (symmetric relations) on n unlabeled vertices with at most n edges.

Terms

    a(0) =1a(1) =2a(2) =2a(3) =4a(4) =8a(5) =17a(6) =39a(7) =92a(8) =227a(9) =573a(10) =1482a(11) =3883a(12) =10343a(13) =27786a(14) =75392a(15) =205933a(16) =566166a(17) =1564316a(18) =4342431a(19) =12100382a(20) =33836606a(21) =94903889a(22) =266914438a(23) =752517020a(24) =2126292931a(25) =6020035120a(26) =17075411671a(27) =48514471709a(28) =138051863755a(29) =393397897262

External references