Number of acyclic edge covers of the complete bipartite graph K_{n,2}.

Terms

a(0) =1a(1) =6a(2) =18a(3) =46a(4) =110a(5) =254a(6) =574a(7) =1278a(8) =2814a(9) =6142a(10) =13310a(11) =28670a(12) =61438a(13) =131070a(14) =278526a(15) =589822a(16) =1245182a(17) =2621438a(18) =5505022a(19) =11534334a(20) =24117246a(21) =50331646a(22) =104857598a(23) =218103806a(24) =452984830a(25) =939524094a(26) =1946157054a(27) =4026531838a(28) =8321499134a(29) =17179869182