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1,2
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 2.]
a(n) = (A000203 + A145390)/2. [Rutherford] - N. J. A. Sloane, Mar 13 2009
Sequence in context: A085180 A114750 A234923 * A057756 A160051 A082746
Adjacent sequences: A145388 A145389 A145390 * A145392 A145393 A145394
nonn
N. J. A. Sloane, Feb 23 2009
approved