Number of words of length n in a certain language.

Terms

a(0) =1a(1) =2a(2) =6a(3) =12a(4) =22a(5) =34a(6) =52a(7) =74a(8) =102a(9) =134a(10) =176a(11) =222a(12) =280a(13) =344a(14) =416a(15) =496a(16) =592a(17) =694a(18) =814a(19) =942a(20) =1082a(21) =1232a(22) =1404a(23) =1584a(24) =1784a(25) =1996a(26) =2226a(27) =2468a(28) =2738a(29) =3016