1,4

Table of n, a(n) for n=1..70.

John S. Rutherford, Sublattice enumeration. IV. Equivalence classes of plane sublattices by parent Patterson symmetry and colour lattice group type, Acta Cryst. (2009). A65, 156-163. [See Table 4.]

a(n) = (A001615(n) - A000086(n))/3. - Andrey Zabolotskiy, May 09 2018

Cf. A000086 (primitive hexagonal sublattices), A002324 (all hexagonal sublattices), A145394 (all sublattices), A001615, A304182.

Sequence in context: A033097 A036845 A094269 * A054536 A293664 A001316

Adjacent sequences: A157224 A157225 A157226 * A157228 A157229 A157230

nonn

N. J. A. Sloane, Feb 25 2009

New name and more terms from Andrey Zabolotskiy, May 09 2018

approved