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A054345 Number of inequivalent sublattices of index n in square lattice, where two lattices are considered equivalent if one can be rotated to give the other. 4
1, 1, 2, 2, 4, 3, 6, 4, 8, 7, 8, 6, 14, 7, 12, 10, 16, 9, 20, 10, 18, 16, 18, 12, 30, 13, 20, 20, 28, 15, 30, 16, 32, 24, 26, 20, 46, 19, 30, 26, 38, 21, 48, 22, 42, 33, 36, 24, 62, 29, 38, 34, 46, 27, 60, 30, 60, 40, 44, 30, 70, 31, 48, 52, 64, 33, 72, 34, 60, 48, 60 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

Table of n, a(n) for n=0..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. - From N. J. A. Sloane, Feb 23 2009

Index entries for sequences related to sublattices

EXAMPLE

For n = 1, 2, 3, 4 the sublattices are generated by the rows of:

[1 0] [2 0] [2 0] [3 0] [3 0] [4 0] [4 0] [2 0] [2 0]

[0 1] [0 1] [1 1] [0 1] [1 1] [0 1] [1 1] [0 2] [1 2].

CROSSREFS

Cf. A003051, A001615, A054346, A054384.

Sequence in context: A161660 A060766 A029578 * A060367 A267451 A062968

Adjacent sequences:  A054342 A054343 A054344 * A054346 A054347 A054348

KEYWORD

nonn,easy,nice

AUTHOR

N. J. A. Sloane, May 06 2000

STATUS

approved

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Last modified June 25 00:41 EDT 2017. Contains 288708 sequences.