Number of permutations of length n in the class of juxtapositions of 321-avoiders with 21-avoiders.

A278301

Number of permutations of length n in the class of juxtapositions of 321-avoiders with 21-avoiders.

Terms

    a(0) =1a(1) =1a(2) =2a(3) =6a(4) =23a(5) =98a(6) =434a(7) =1949a(8) =8803a(9) =39888a(10) =181201a(11) =825201a(12) =3767757a(13) =17249560a(14) =79191480a(15) =364585230a(16) =1683208515a(17) =7792546040a(18) =36174065285a(19) =168367375735a(20) =785637327745

External references