

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
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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

T. D. Noe, Rows n=1..50 of triangle, flattened
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: A046653 A308897 A162190 * A205123 A108715 A119671
Adjacent sequences: A134289 A134290 A134291 * A134293 A134294 A134295


KEYWORD

nice,nonn,look,tabf


AUTHOR

T. D. Noe, Oct 16 2007


STATUS

approved



