Number of connected functions on n points with a loop of length 8.

Terms

a(0) =1a(1) =1a(2) =6a(3) =25a(4) =104a(5) =384a(6) =1380a(7) =4729a(8) =15806a(9) =51478a(10) =164788a(11) =519296a(12) =1617066a(13) =4983855a(14) =15233671a(15) =46235252a(16) =139506803a(17) =418838281a(18) =1252174861a(19) =3730058316a(20) =11077154790a(21) =32808815240a(22) =96953599162a(23) =285945645659a(24) =841909040785