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A080738
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Array read by rows in which 0-th row is {1,2}; for n>0, n-th row gives finite orders of 2n X 2n integer matrices that are not orders of 2n-1 X 2n-1 integer matrices.
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5
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1, 2, 3, 4, 6, 5, 8, 10, 12, 7, 9, 14, 15, 18, 20, 24, 30, 16, 21, 28, 36, 40, 42, 60, 11, 22, 35, 45, 48, 56, 70, 72, 84, 90, 120, 13, 26, 33, 44, 63, 66, 80, 105, 126, 140, 168, 180, 210, 39, 52, 55, 78, 88, 110, 112, 132, 144, 240, 252, 280, 360, 420, 17, 32, 34, 65, 77
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,2
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COMMENTS
| A080739 gives number of elements in n-th row.
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REFERENCES
| J. Bamberg, G. Cairns and D. Kilminster, The crystallographic restriction, permutations and Goldbach's conjecture, Amer. Math. Monthly, 110 (March 2003), 202-209.
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FORMULA
| Set of finite orders of n X n integer matrices = {m : A080737(m) <= n}.
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EXAMPLE
| 1,2; 3,4,6; 5,8,10,12; 7,9,14,15,18,20,24,30; ...
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CROSSREFS
| Cf. A080737, A080739-A080742.
Sequence in context: A194507 A118316 A197756 * A032447 A058213 A080997
Adjacent sequences: A080735 A080736 A080737 * A080739 A080740 A080741
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KEYWORD
| nonn,tabf,easy
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AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com), Mar 08 2003
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EXTENSIONS
| More terms from Vladeta Jovovic (vladeta(AT)eunet.rs), Mar 09 2003
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