1,3

Nonnegative integers of the form x^2 + x*y + 4y^2, discriminant -15. - Ray Chandler, Jul 12 2014

Table of n, a(n) for n=1..60.

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

Primes are in A033212.

Sequence in context: A310665 A005659 A010462 * A242664 A084662 A137167

Adjacent sequences: A028954 A028955 A028956 * A028958 A028959 A028960

nonn

N. J. A. Sloane.

More terms from Larry Reeves (larryr(AT)acm.org), Mar 29 2000

approved