Number of permutations of length n which avoid the patterns 123, 3142, 4312; or avoid the patterns 123, 3421, 4231.
A116721
Number of permutations of length n which avoid the patterns 123, 3142, 4312; or avoid the patterns 123, 3421, 4231.
Terms
- a(0) =1a(1) =2a(2) =5a(3) =12a(4) =24a(5) =42a(6) =67a(7) =100a(8) =142a(9) =194a(10) =257a(11) =332a(12) =420a(13) =522a(14) =639a(15) =772a(16) =922a(17) =1090a(18) =1277a(19) =1484a(20) =1712a(21) =1962a(22) =2235a(23) =2532a(24) =2854a(25) =3202a(26) =3577a(27) =3980a(28) =4412a(29) =4874
External references
- oeis: A116721