Number of compositions (ordered partitions) of n that are concave-down sequences.

Terms

a(0) =1a(1) =1a(2) =2a(3) =4a(4) =6a(5) =9a(6) =14a(7) =18a(8) =24a(9) =34a(10) =42a(11) =52a(12) =68a(13) =82a(14) =101a(15) =126a(16) =147a(17) =175a(18) =213a(19) =246a(20) =289a(21) =344a(22) =392a(23) =453a(24) =530a(25) =598a(26) =687a(27) =791a(28) =885a(29) =1007