Elements of the Motzkin words sub-operad Motz of TN generated by 00 and 010.

Terms

a(0) =1a(1) =11a(2) =111a(3) =121a(4) =1111a(5) =1121a(6) =1211a(7) =1221a(8) =11111a(9) =11121a(10) =11211a(11) =11221a(12) =12111a(13) =12121a(14) =12211a(15) =12221a(16) =12321a(17) =111111a(18) =111121a(19) =111211a(20) =111221a(21) =112111a(22) =112121a(23) =112211a(24) =112221a(25) =112321a(26) =121111a(27) =121121a(28) =121211a(29) =121221