The number of 321-avoiding linear extensions of the comb poset K_{4,n}^beta.

A275942

The number of 321-avoiding linear extensions of the comb poset K_{4,n}^beta.

Terms

    a(0) =1a(1) =55a(2) =1866a(3) =49523a(4) =1147175a(5) =24446239a(6) =492996938a(7) =9566197039a(8) =180473841477

External references