Number of excursions of length n with Motzkin-steps avoiding the consecutive steps UU, HH, HD and DH.

A329692

Number of excursions of length n with Motzkin-steps avoiding the consecutive steps UU, HH, HD and DH.

Terms

    a(0) =1a(1) =1a(2) =1a(3) =1a(4) =1a(5) =2a(6) =2a(7) =4a(8) =5a(9) =8a(10) =13a(11) =18a(12) =32a(13) =46a(14) =77a(15) =123a(16) =192a(17) =325a(18) =506a(19) =849a(20) =1375a(21) =2245a(22) =3750a(23) =6085a(24) =10206a(25) =16798a(26) =27936a(27) =46689a(28) =77389a(29) =130048

External references