A272933 Numbers of the form x^2 + 12*y^2.

0, 1, 4, 9, 12, 13, 16, 21, 25, 28, 36, 37, 48, 49, 52, 57, 61, 64, 73, 76, 81, 84, 93, 97, 100, 108, 109, 112, 117, 121, 124, 129, 133, 144, 148, 156, 157, 169, 172, 181, 189, 192, 193, 196, 201, 208, 217, 225, 228, 229, 237, 241, 244, 252, 256, 268, 273, 277

Offset: 1

Author

Arkadiusz Wesolowski, May 11 2016

Keywords

• nonn
• easy

Comments

x^2 + 12*y^2 has discriminant -48.

All terms are congruent to {0, 1, 4, 9, 12, 13, 16, 21, 25, 28} (mod 36).

Norms of numbers in Z[sqrt(-12)].

Crossrefs

Cf. A003136. A068228 gives the primes.

Programs

Magma

[n: n in [0..277] | NormEquation(12, n) eq true];