Numbers of quasi-espalier polycubes of a given volume (number of atomic cells).

Terms

a(0) =1a(1) =2a(2) =4a(3) =7a(4) =12a(5) =18a(6) =29a(7) =42a(8) =61a(9) =87a(10) =122a(11) =167a(12) =229a(13) =306a(14) =409a(15) =538a(16) =705a(17) =915a(18) =1182a(19) =1509a(20) =1927a(21) =2438a(22) =3075a(23) =3854a(24) =4814a(25) =5985a(26) =7416a(27) =9144a(28) =11253a(29) =13784