Number of permutations of the multiset {1,1,2,2,3,3,...,n+1,n+1} avoiding the permutation patterns {132, 231, 2134}.

A181510

Number of permutations of the multiset {1,1,2,2,3,3,...,n+1,n+1} avoiding the permutation patterns {132, 231, 2134}.

Terms

    a(0) =6a(1) =18a(2) =34a(3) =54a(4) =78a(5) =106a(6) =138a(7) =174a(8) =214a(9) =258a(10) =306a(11) =358a(12) =414a(13) =474a(14) =538a(15) =606a(16) =678a(17) =754a(18) =834a(19) =918a(20) =1006a(21) =1098a(22) =1194a(23) =1294a(24) =1398a(25) =1506a(26) =1618a(27) =1734a(28) =1854a(29) =1978

External references