Number of sublattices of index n in generic 3-dimensional lattice.

Terms

a(0) =1a(1) =7a(2) =13a(3) =35a(4) =31a(5) =91a(6) =57a(7) =155a(8) =130a(9) =217a(10) =133a(11) =455a(12) =183a(13) =399a(14) =403a(15) =651a(16) =307a(17) =910a(18) =381a(19) =1085a(20) =741a(21) =931a(22) =553a(23) =2015a(24) =806a(25) =1281a(26) =1210a(27) =1995a(28) =871a(29) =2821