The number of edge-rooted unlabeled connected graphs with n edges.

Terms

a(0) =1a(1) =1a(2) =4a(3) =10a(4) =32a(5) =101a(6) =346a(7) =1220a(8) =4517a(9) =17338a(10) =69107a(11) =285009a(12) =1215015a(13) =5344224a(14) =24223641a(15) =113001129a(16) =541913075a(17) =2668817544a(18) =13484234188a(19) =69831773559a(20) =370361639587