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

Terms

a(0) =1a(1) =1a(2) =2a(3) =5a(4) =10a(5) =20a(6) =43a(7) =84a(8) =168a(9) =332a(10) =650a(11) =1255a(12) =2428a(13) =4636a(14) =8827a(15) =16702a(16) =31457a(17) =58919a(18) =109977a(19) =204286a(20) =378135a(21) =697240a(22) =1281315a(23) =2346612a(24) =4284654a(25) =7799248a(26) =14157079a(27) =25626996a(28) =46269838a(29) =83330373