Three-quadrant Ferrers graphs that partition n.

Terms

a(0) =1a(1) =2a(2) =5a(3) =11a(4) =24a(5) =48a(6) =95a(7) =178a(8) =328a(9) =585a(10) =1025a(11) =1754a(12) =2958a(13) =4897a(14) =8002a(15) =12889a(16) =20523a(17) =32289a(18) =50296a(19) =77550a(20) =118521a(21) =179553a(22) =269881a(23) =402532a(24) =596178a(25) =876942a(26) =1281777a(27) =1862015a(28) =2689405a(29) =3862891