cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A225071 Number of Gaussian primes at taxicab distance 2n-1 from the origin.

Original entry on oeis.org

0, 12, 16, 20, 16, 28, 24, 32, 32, 36, 24, 36, 64, 32, 48, 44, 32, 72, 64, 48, 72, 60, 56, 60, 40, 56, 72, 112, 64, 76, 88, 56, 136, 92, 80, 76, 88, 72, 64, 108, 72, 124, 160, 88, 112, 104, 64, 144, 112, 80, 144, 132, 80, 140, 128, 104, 160, 160, 104, 112, 136
Offset: 1

Views

Author

T. D. Noe, May 03 2013

Keywords

Comments

Except for 1+I, 1-I, -1+I, and -1-I, all Gaussian primes are an odd taxicab distance from the origin.

Crossrefs

Cf. A218858.

Programs

  • Mathematica
    Table[cnt = 0; Do[If[PrimeQ[n - i + I*i, GaussianIntegers -> True], cnt++], {i, 0, n}]; Do[If[PrimeQ[i - n + I*i, GaussianIntegers -> True], cnt++], {i, n - 1, 0, -1}]; Do[If[PrimeQ[i - n - I*i, GaussianIntegers -> True], cnt++], {i, 1, n}]; Do[If[PrimeQ[n - i - I*i, GaussianIntegers -> True], cnt++], {i, n - 1, 1, -1}]; cnt, {n, 1, 200, 2}]