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A134292
Triangle in which row n is the lexicographically earliest solution to the prime circle problem for 2n.
1
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
OFFSET
1,2
COMMENTS
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.
REFERENCES
R. K. Guy, Unsolved Problems Number Theory, Section C1.
LINKS
Eric Weisstein's World of Mathematics, Prime Circle
EXAMPLE
Triangle begins:
1, 2;
1, 2, 3, 4;
1, 4, 3, 2, 5, 6;
1, 2, 3, 8, 5, 6, 7, 4;
...
CROSSREFS
Cf. A051252 (number of solutions for each n), A051237 (prime pyramid).
Sequence in context: A353293 A162190 A349325 * A344006 A353319 A205123
KEYWORD
nice,nonn,look,tabf
AUTHOR
T. D. Noe, Oct 16 2007
STATUS
approved