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A134292
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Triangle in which row n is the lexicographically earliest solution to the prime circle problem for 2n.
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1
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1, 2, 1, 2, 3, 4, 1, 4, 3, 2, 5, 6, 1, 2, 3, 8, 5, 6, 7, 4, 1, 2, 3, 4, 7, 6, 5, 8, 9, 10, 1, 2, 3, 4, 7, 6, 5, 12, 11, 8, 9, 10, 1, 2, 3, 4, 7, 6, 13, 10, 9, 14, 5, 8, 11, 12, 1, 2, 3, 4, 7, 6, 5, 12, 11, 8, 9, 14, 15, 16, 13, 10, 1, 2, 3, 4, 7, 6, 5, 8, 9, 10, 13, 16, 15, 14, 17, 12, 11, 18, 1, 2, 3
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OFFSET
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1,2
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COMMENTS
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In the prime circle problem we seek to arrange the numbers 1 to 2n around a circle so that the sum of each pair of adjacent numbers is prime. To display the solution, we unroll the circle starting at 1.
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REFERENCES
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R. K. Guy, Unsolved Problems Number Theory, Section C1.
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LINKS
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EXAMPLE
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Triangle begins:
1, 2;
1, 2, 3, 4;
1, 4, 3, 2, 5, 6;
1, 2, 3, 8, 5, 6, 7, 4;
...
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CROSSREFS
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Cf. A051252 (number of solutions for each n), A051237 (prime pyramid).
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KEYWORD
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AUTHOR
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STATUS
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approved
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