Number of permutations of [n] avoiding {4231, 3142, 1234}.

Terms

a(0) =1a(1) =1a(2) =2a(3) =6a(4) =21a(5) =71a(6) =217a(7) =599a(8) =1514a(9) =3550a(10) =7801a(11) =16193a(12) =31956a(13) =60282a(14) =109214a(15) =190816a(16) =322679a(17) =529823a(18) =847060a(19) =1321888a(20) =2017991a(21) =3019425a(22) =4435575a(23) =6406973a(24) =9112072a(25) =12775076a(26) =17674931a(27) =24155587a(28) =32637646a(29) =43631516