Number of strict compositions of n with no three consecutive parts in arithmetic progression.

Terms

a(0) =1a(1) =1a(2) =1a(3) =3a(4) =3a(5) =5a(6) =9a(7) =13a(8) =19a(9) =23a(10) =51a(11) =57a(12) =91a(13) =117a(14) =179a(15) =283a(16) =381a(17) =531a(18) =737a(19) =1017a(20) =1335a(21) =2259a(22) =2745a(23) =3983a(24) =5289a(25) =7367a(26) =9413a(27) =13155a(28) =19461a(29) =25129