Number of simple connected graphs on n unlabeled nodes with exactly 2 non-overlapping cycles.

A381470

Number of simple connected graphs on n unlabeled nodes with exactly 2 non-overlapping cycles.

Terms

    a(0) =1a(1) =4a(2) =21a(3) =85a(4) =345a(5) =1289a(6) =4713a(7) =16622a(8) =57535a(9) =195212a(10) =653318a(11) =2158866a(12) =7063333a(13) =22906699a(14) =73742762a(15) =235863378a(16) =750187968a(17) =2374249283a(18) =7481414941a(19) =23482536967a(20) =73449564533a(21) =229016163367a(22) =712044375528

External references