The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 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 (list; graph; refs; listen; history; text; internal format)
 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

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified March 30 12:10 EDT 2020. Contains 333125 sequences. (Running on oeis4.)