Number of sets of nonempty multisets of nonempty sets of positive integers with total sum n.

Terms

a(0) =1a(1) =1a(2) =2a(3) =6a(4) =12a(5) =28a(6) =62a(7) =134a(8) =285a(9) =610a(10) =1277a(11) =2661a(12) =5506a(13) =11305a(14) =23064a(15) =46803a(16) =94406a(17) =189484a(18) =378522a(19) =752668a(20) =1490319a(21) =2939093a(22) =5774065a(23) =11302564a(24) =22048496a(25) =42869613a(26) =83091843a(27) =160569590a(28) =309398958a(29) =594532990