Number of unlabeled functions on n nodes that have at least one fixed point.

Terms

a(0) =0a(1) =1a(2) =2a(3) =5a(4) =13a(5) =34a(6) =90a(7) =243a(8) =660a(9) =1818a(10) =5045a(11) =14102a(12) =39639a(13) =111982a(14) =317533a(15) =903464a(16) =2577724a(17) =7372542a(18) =21130127a(19) =60672017a(20) =174492633a(21) =502568607a(22) =1449360241a(23) =4184719174a(24) =12095325486a(25) =34993693260a(26) =101332159421a(27) =293669741860a(28) =851722291650