Solution to the Dancing School Problem with n girls and n+4 boys: f(n,4).

Terms

a(0) =5a(1) =21a(2) =76a(3) =246a(4) =738a(5) =2108a(6) =5794a(7) =15458a(8) =40296a(9) =103129a(10) =260019a(11) =647617a(12) =1596800a(13) =3904260a(14) =9479292a(15) =22879520a(16) =54947836a(17) =131406732a(18) =313129592a(19) =743878505a(20) =1762572329a(21) =4167010597a(22) =9832766588a(23) =23164353834