Number of permutations of length n which avoid the patterns 321, 12354.

Terms

a(0) =1a(1) =1a(2) =2a(3) =5a(4) =14a(5) =41a(6) =113a(7) =277a(8) =607a(9) =1212a(10) =2245a(11) =3913a(12) =6488a(13) =10319a(14) =15845a(15) =23609a(16) =34273a(17) =48634a(18) =67641a(19) =92413a(20) =124258a(21) =164693a(22) =215465a(23) =278573a(24) =356291a(25) =451192a(26) =566173a(27) =704481a(28) =869740a(29) =1065979