Number of 5-block ordered tricoverings of an unlabeled n-set.

Terms

a(0) =0a(1) =0a(2) =60a(3) =375a(4) =1392a(5) =4020a(6) =9960a(7) =22200a(8) =45730a(9) =88543a(10) =163000a(11) =287650a(12) =489610a(13) =807625a(14) =1295944a(15) =2029165a(16) =3108220a(17) =4667690a(18) =6884660a(19) =9989345a(20) =14277740a(21) =20126570a(22) =28010840a(23) =38524310a(24) =52403246a(25) =70553825a(26) =94083600a(27) =124337460a(28) =162938550a(29) =211834647