Number of ternary paths of length 3*n having exactly 2 hills.

A374836

Number of ternary paths of length 3*n having exactly 2 hills.

Terms

    a(0) =0a(1) =0a(2) =1a(3) =0a(4) =6a(5) =21a(6) =114a(7) =597a(8) =3278a(9) =18420a(10) =105618a(11) =615331a(12) =3632352a(13) =21678975a(14) =130598887a(15) =793085742a(16) =4849791942a(17) =29838388707a(18) =184573315170

External references