A247881 Numbers of the form x^2 + 13y^2.

0, 1, 4, 9, 13, 14, 16, 17, 22, 25, 29, 36, 38, 49, 52, 53, 56, 61, 62, 64, 68, 77, 81, 88, 94, 100, 101, 113, 116, 117, 118, 121, 126, 133, 134, 142, 144, 152, 153, 157, 166, 169, 173, 181, 182, 196, 198, 208, 209, 212, 217, 221, 224, 225, 233, 238, 244, 248, 256, 257, 261, 269

Offset

1,3

Comments

Norms of numbers in Z[sqrt(-13)].

Links

Table of n, a(n) for n=1..62.

Crossrefs

Cf. A033210 (subsequence of primes).

Sequence in context: A135740 A312870 A312871 * A010412 A033662 A312872

Adjacent sequences: A247878 A247879 A247880 * A247882 A247883 A247884

Keyword

easy,nonn

Author

Alonso del Arte, Sep 25 2014

Status

approved