Total area of all n-celled polyominoes.

Terms

a(0) =1a(1) =2a(2) =6a(3) =20a(4) =60a(5) =210a(6) =756a(7) =2952a(8) =11565a(9) =46550a(10) =187803a(11) =763200a(12) =3101683a(13) =12627594a(14) =51398640a(15) =209268080a(16) =851834453a(17) =3467196936a(18) =14109860408a(19) =57413439000a(20) =233584274238a(21) =950220869136