Number of permutations avoiding the patterns {1432,2431,3412,3421,4132,4231,4312,4321}; number of strong sorting class based on 1432.

A111282

Number of permutations avoiding the patterns {1432,2431,3412,3421,4132,4231,4312,4321}; number of strong sorting class based on 1432.

Terms

    a(0) =1a(1) =2a(2) =6a(3) =16a(4) =42a(5) =110a(6) =288a(7) =754a(8) =1974a(9) =5168a(10) =13530a(11) =35422a(12) =92736a(13) =242786a(14) =635622a(15) =1664080a(16) =4356618a(17) =11405774a(18) =29860704a(19) =78176338a(20) =204668310a(21) =535828592a(22) =1402817466a(23) =3672623806a(24) =9615053952a(25) =25172538050a(26) =65902560198a(27) =172535142544

External references