Number of permutations of length n which avoid the patterns 1234, 1432, 2413.

Terms

a(0) =1a(1) =2a(2) =6a(3) =21a(4) =71a(5) =229a(6) =726a(7) =2299a(8) =7296a(9) =23180a(10) =73648a(11) =233935a(12) =742924a(13) =2359143a(14) =7491146a(15) =23786672a(16) =75528789a(17) =239820410a(18) =761475614a(19) =2417816525a(20) =7676955811a(21) =24375507011a(22) =77395827653a(23) =245742882637a(24) =780268393400