OFFSET
1,1
COMMENTS
Nonnegative numbers of the form 8x^2 - y^2. - Jon E. Schoenfield, Jun 03 2022
LINKS
N. J. A. Sloane et al., Binary Quadratic Forms and OEIS (Index to related sequences, programs, references)
EXAMPLE
4 is in the sequence because x^2 - 6xy + y^2 + 4 = 0 has integer solutions, for example (x, y) = (1, 5).
CROSSREFS
Cf. A001653 (k = 4), A006452 (k = 7), A001541 (k = 8), A075870 (k = 16), A156066 (k = 23), A217975 (k = 28), A003499 (k = 32), A075841 (k = 36), A077443 (k = 56).
For a list of sequences giving numbers and/or primes represented by binary quadratic forms, see the "Binary Quadratic Forms and OEIS" link.
KEYWORD
nonn
AUTHOR
Colin Barker, Feb 10 2014
STATUS
approved