Number of (2,1)-separable partitions of n; see Comments.

Terms

a(0) =0a(1) =0a(2) =1a(3) =0a(4) =1a(5) =2a(6) =1a(7) =2a(8) =3a(9) =3a(10) =4a(11) =6a(12) =6a(13) =8a(14) =11a(15) =12a(16) =15a(17) =20a(18) =22a(19) =28a(20) =35a(21) =40a(22) =49a(23) =61a(24) =70a(25) =85a(26) =103a(27) =120a(28) =143a(29) =173