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A325088
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Prime numbers congruent to 1 or 169 modulo 240 representable neither by x^2 + 150*y^2 nor by x^2 + 960*y^2.
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3
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241, 409, 1201, 1609, 2089, 2161, 3049, 3121, 3529, 4561, 4729, 4969, 5281, 6481, 6961, 7129, 7369, 7681, 8089, 8161, 9049, 11689, 12241, 12721, 12889, 13441, 13921, 14401, 16249, 17449, 17929, 19441, 19609, 19681, 20161, 20641, 20809, 21121, 21841, 23041
(list;
graph;
refs;
listen;
history;
text;
internal format)
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OFFSET
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1,1
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COMMENTS
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Brink showed that prime numbers congruent to 1 or 169 modulo 240 are representable by both or neither of the quadratic forms x^2 + 150*y^2 and x^2 + 960*y^2. A325087 corresponds to those representable by both, and this sequence corresponds to those representable by neither.
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LINKS
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EXAMPLE
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Regarding 241:
- 241 is a prime number,
- 241 = 1*240 + 1,
- 241 is neither representable by x^2 + 150*y^2 nor by x^2 + 960*y^2,
- hence 241 belongs to this sequence.
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PROG
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(PARI) See Links section.
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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