Number of compositions of n into parts 3,4 where both parts are always present.

Terms

a(0) =0a(1) =0a(2) =0a(3) =0a(4) =0a(5) =0a(6) =0a(7) =2a(8) =0a(9) =0a(10) =3a(11) =3a(12) =0a(13) =4a(14) =6a(15) =4a(16) =5a(17) =10a(18) =10a(19) =11a(20) =15a(21) =20a(22) =22a(23) =27a(24) =35a(25) =43a(26) =49a(27) =63a(28) =79a(29) =92