Number of stacks, or planar partitions of n; also weakly unimodal compositions of n.

Terms

a(0) =1a(1) =1a(2) =2a(3) =4a(4) =8a(5) =15a(6) =27a(7) =47a(8) =79a(9) =130a(10) =209a(11) =330a(12) =512a(13) =784a(14) =1183a(15) =1765a(16) =2604a(17) =3804a(18) =5504a(19) =7898a(20) =11240a(21) =15880a(22) =22277a(23) =31048a(24) =43003a(25) =59220a(26) =81098a(27) =110484a(28) =149769a(29) =202070