Number of unlabeled graphs with at least one cycle in which every connected component has at most one cycle.
A138237
Number of unlabeled graphs with at least one cycle in which every connected component has at most one cycle.
Terms
- a(0) =1a(1) =3a(2) =9a(3) =26a(4) =71a(5) =197a(6) =543a(7) =1507a(8) =4186a(9) =11722a(10) =32883a(11) =92724a(12) =262179a(13) =743792a(14) =2115019a(15) =6028779a(16) =17217093a(17) =49258009a(18) =141142096a(19) =404997704a(20) =1163569094a(21) =3346830818a(22) =9636723582a(23) =27774427243a(24) =80121104084a(25) =231317022483a(26) =668346261557
External references
- oeis: A138237