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A066514
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Number of subgroups of the group GL(2,Z_n) of invertible 2 X 2 matrices mod n (sequence A000252).
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2
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1, 6, 55, 234, 466, 758, 1704, 24587, 6656, 6718, 6428, 114210, 17158, 26180, 135869, 701426, 33277, 126920, 52320, 1341656, 469872, 87924, 48976, 50257306, 140918, 291060, 348528, 3952920, 175438, 3685062, 285952, 12024029, 1657948, 567994, 4624192, 15262640, 539046, 838096
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OFFSET
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1,2
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LINKS
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PROG
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(GAP) c := CyclicGroup(n); aut := AutomorphismGroup(DirectProduct(c, c)); lat := LatticeSubgroups(aut);
(Magma) [&+[s`length : s in Subgroups(GL(2, ResidueClassRing(n)))] : n in [2..10]]; // Robin Visser, Aug 09 2023
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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Sharon Sela (sharonsela(AT)hotmail.com), Jan 04 2002
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EXTENSIONS
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STATUS
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approved
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