Number of primitive sublattices of index n in hexagonal lattice: triples x,y,z from Z/nZ with x+y+z = 0, discarding any triple that can be obtained from another by multiplying by a unit and permuting.
A003050
Number of primitive sublattices of index n in hexagonal lattice: triples x,y,z from Z/nZ with x+y+z = 0, discarding any triple that can be obtained from another by multiplying by a unit and permuting.
Terms
- a(0) =1a(1) =1a(2) =2a(3) =2a(4) =2a(5) =3a(6) =3a(7) =4a(8) =3a(9) =4a(10) =3a(11) =6a(12) =4a(13) =5a(14) =6a(15) =6a(16) =4a(17) =7a(18) =5a(19) =8a(20) =8a(21) =7a(22) =5a(23) =12a(24) =6a(25) =8a(26) =7a(27) =10a(28) =6a(29) =14
External references
- oeis: A003050