Number of connected functions on n points with a single labeled point.

Terms

a(0) =0a(1) =1a(2) =3a(3) =9a(4) =27a(5) =81a(6) =242a(7) =722a(8) =2150a(9) =6395a(10) =19003a(11) =56428a(12) =167458a(13) =496724a(14) =1472835a(15) =4365692a(16) =12936998a(17) =38327764a(18) =113529027a(19) =336221554a(20) =995586119a(21) =2947641940a(22) =8726093434a(23) =25829729702a(24) =76450357119a(25) =226257478851a(26) =669566448376