Number of non-isomorphic connected multiset partitions of weight n into singletons or strict pairs.

Terms

a(0) =1a(1) =1a(2) =2a(3) =2a(4) =5a(5) =6a(6) =15a(7) =21a(8) =49a(9) =82a(10) =184a(11) =341a(12) =766a(13) =1530a(14) =3428a(15) =7249a(16) =16394a(17) =36009a(18) =82492a(19) =186485a(20) =433096a(21) =1001495a(22) =2358182a(23) =5554644a(24) =13255532a(25) =31718030a(26) =76656602a(27) =185982207a(28) =454889643a(29) =1117496012