1,4

Table of n, a(n) for n=1..69.

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) - A060594(n))/2. - Andrey Zabolotskiy, May 09 2018

Cf. A060594 (primitive mirror-symmetric sublattices), A145390 (all mirror-symmetric sublattices), A145391 (all sublattices), A001615, A304182.

Sequence in context: A308143 A308515 A128134 * A174608 A130327 A224361

Adjacent sequences: A157220 A157221 A157222 * A157224 A157225 A157226

nonn

N. J. A. Sloane, Feb 25 2009

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

approved