Solution to the Dancing School Problem with n girls and n+3 boys: f(n,3).

Terms

a(0) =4a(1) =13a(2) =36a(3) =90a(4) =212a(5) =478a(6) =1044a(7) =2227a(8) =4664a(9) =9627a(10) =19640a(11) =39684a(12) =79544a(13) =158364a(14) =313464a(15) =617365a(16) =1210588a(17) =2364713a(18) =4603388a(19) =8934142a(20) =17291756a(21) =33385018a(22) =64311660a(23) =123634471a(24) =237233712a(25) =454429239a(26) =869095472a(27) =1659708488