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A157224 Number of primitive inequivalent (up to Pi/2 rotation) nonsquare sublattices of square lattice of index n. 2

%I #17 May 04 2021 10:44:18

%S 0,1,2,3,2,6,4,6,6,8,6,12,6,12,12,12,8,18,10,18,16,18,12,24,14,20,18,

%T 24,14,36,16,24,24,26,24,36,18,30,28,36,20,48,22,36,36,36,24,48,28,44,

%U 36,42,26,54,36,48,40,44,30,72,30,48,48,48,40,72,34,54

%N Number of primitive inequivalent (up to Pi/2 rotation) nonsquare sublattices of square lattice of index n.

%H John S. Rutherford, <a href="http://dx.doi.org/10.1107/S010876730804333X">Sublattice enumeration. IV. Equivalence classes of plane sublattices by parent Patterson symmetry and colour lattice group type</a>, Acta Cryst. (2009). A65, 156-163. [See Table 4.]

%F a(n) = (A001615(n) - A000089(n))/2. - _Andrey Zabolotskiy_, May 09 2018

%Y Cf. A000089 (primitive square sublattices), A002654 (all square sublattices), A145392 (all sublattices), A001615, A304182.

%K nonn

%O 1,3

%A _N. J. A. Sloane_, Feb 25 2009

%E New name and more terms from _Andrey Zabolotskiy_, May 09 2018

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Last modified March 28 20:05 EDT 2024. Contains 371254 sequences. (Running on oeis4.)