A244032 Positive numbers n such that there exists a positive number m != n such that x^2+ny^2 and x^2+my^2 represent the same odd primes.

1, 4, 8, 9, 12, 16, 24, 45, 48, 72, 80, 120, 240

Offset

1,2

Comments

There are no other terms for which both n and m are < 100000.

Links

Table of n, a(n) for n=1..13.

William C. Jagy and Irving Kaplansky, Positive definite binary quadratic forms that represent the same primes [Cached copy]

N. J. A. Sloane et al., Binary Quadratic Forms and OEIS (Index to related sequences, programs, references)

Example

For example, 9 and 12 are members because the odd primes (in fact all the primes) represented by x^2+9y^2 and x^2+12y^2 are the same - see A068228.

Crossrefs

Cf. A068228.

Sequence in context: A069168 A374037 A102211 * A321454 A353834 A319302

Adjacent sequences: A244029 A244030 A244031 * A244033 A244034 A244035

Keyword

nonn

Author

N. J. A. Sloane, Jun 22 2014

Status

approved