Number of trees on n vertices with an odd number of leaves.

Terms

a(0) =0a(1) =1a(2) =0a(3) =0a(4) =1a(5) =1a(6) =3a(7) =5a(8) =11a(9) =22a(10) =52a(11) =115a(12) =273a(13) =644a(14) =1573a(15) =3856a(16) =9644a(17) =24279a(18) =61893a(19) =158889a(20) =411428a(21) =1072028a(22) =2811609a(23) =7413463a(24) =19649241a(25) =52316944a(26) =139894857a(27) =375528799a(28) =1011716551a(29) =2734772854