Number of twice-partitions of n into partitions with weakly decreasing lengths.

Terms

a(0) =1a(1) =1a(2) =3a(3) =6a(4) =14a(5) =26a(6) =56a(7) =102a(8) =205a(9) =372a(10) =708a(11) =1260a(12) =2345a(13) =4100a(14) =7388a(15) =12819a(16) =22603a(17) =38658a(18) =67108a(19) =113465a(20) =193876a(21) =324980a(22) =547640a(23) =909044a(24) =1516609a(25) =2495023a(26) =4118211a(27) =6726997a(28) =11002924a(29) =17836022