A prime triangle is a number triangle whose th row is a permutation
of the integers 1, 2, ..., , beginning with 1 and ending with , such that the sum of every two consecutive
entries is a prime. Rows 2 to 6 are unique,
(OEIS A051237) but there are multiple possibilities starting with row 7. For example, the two possibilities for row 7 are and . The numbers of possible rows ending with , 2, ..., are 1, 1, 1, 1, 1, 1, 2,
4, 7, 24, 80, ... (OEIS A036440).
Guy, R. K. Unsolved Problems in Number Theory, 2nd ed. New York: Springer-Verlag, p. 106,
1994.Kenney, M. J. "Student Math Notes." NCTM News
Bulletin. Nov. 1986.Sloane, N. J. A. Sequences A036440 and A051237
in "The On-Line Encyclopedia of Integer Sequences."
th row is a permutation
of the integers 1, 2, ..., 
, beginning with 1 and ending with 
, such that the sum of every two consecutive
entries is a prime. Rows 2 to 6 are unique,
and 
. The numbers of possible rows ending with 
, 2, ..., are 1, 1, 1, 1, 1, 1, 2,
4, 7, 24, 80, ... (OEIS A036440).
