Number of polycubes of size n and symmetry class E.

Terms

a(0) =0a(1) =0a(2) =0a(3) =1a(4) =6a(5) =28a(6) =126a(7) =520a(8) =2099a(9) =8429a(10) =33676a(11) =135201a(12) =543248a(13) =2195182a(14) =8893547a(15) =36196788a(16) =147739046a(17) =605138811a(18) =2485051070a(19) =10233284681a(20) =42234214910a(21) =174693725151