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A141249
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Numbers n such that the central point of the square n X n lattice sees the minimal number of points.
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2
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1, 21, 33, 45, 73, 81, 193, 201, 241, 273, 313, 381, 421, 445, 453, 661, 693, 861, 885, 913
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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COMMENTS
| These n are the numbers for which A141248(n) is odd. Note that n must be odd. When A141248(n)=1, the central point is the only point seeing the minimal number of points. These numbers are 1 or 9 (mod 12). These numbers also seem to produce cubic n X n X n lattices in which the central point has minimal visibility. Note that for n>1, n+1 is twice a prime power in A141250.
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CROSSREFS
| Cf. A141226.
Sequence in context: A181677 A036382 A119973 * A026068 A176945 A070006
Adjacent sequences: A141246 A141247 A141248 * A141250 A141251 A141252
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KEYWORD
| nonn
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AUTHOR
| T. D. Noe (noe(AT)sspectra.com), Jun 17 2008
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