Number of permutations of length n which avoid the patterns 312, 1324, 3421; or avoid the patterns 312, 1324, 2341, etc.
A116722
Number of permutations of length n which avoid the patterns 312, 1324, 3421; or avoid the patterns 312, 1324, 2341, etc.
Terms
- a(0) =1a(1) =2a(2) =5a(3) =12a(4) =25a(5) =47a(6) =82a(7) =135a(8) =212a(9) =320a(10) =467a(11) =662a(12) =915a(13) =1237a(14) =1640a(15) =2137a(16) =2742a(17) =3470a(18) =4337a(19) =5360a(20) =6557a(21) =7947a(22) =9550a(23) =11387a(24) =13480a(25) =15852a(26) =18527a(27) =21530a(28) =24887a(29) =28625
External references
- oeis: A116722