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.
%I A218858 #15 May 03 2013 19:01:32
%S A218858 0,0,4,12,0,16,0,20,0,16,0,28,0,24,0,32,0,32,0,36,0,24,0,36,0,64,0,32,
%T A218858 0,48,0,44,0,32,0,72,0,64,0,48,0,72,0,60,0,56,0,60,0,40,0,56,0,72,0,
%U A218858 112,0,64,0,76,0,88,0,56,0,136,0,92,0,80,0,76,0,88,0
%N A218858 Number of Gaussian primes at taxicab distance n from the origin.
%C A218858 Except for n = 2, there are no Gaussian primes at an even taxicab distance from the origin. All terms are multiples of 4. See A218859 for this sequence divided by 4.
%C A218858 The arithmetic derivative of Gaussian primes is either 1, -1, I, or -I.
%H A218858 T. D. Noe, <a href="/A218858/b218858.txt">Table of n, a(n) for n = 0..10000</a>
%H A218858 T. D. Noe, <a href="/A218858/a218858.png">Linear plot</a>
%e A218858 In the taxicab distance, the four Gaussian primes closest to the origin are 1+I, -1+I, -i-I, and 1-I. The 12 at taxicab distance 3 are the four reflections of 3, 2+I, and 1+2I.
%t A218858 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, 0, 100}]
%Y A218858 Cf. A055025 (norms of Gaussian primes).
%Y A218858 Cf. A222593 (first-quadrant Gaussian primes).
%Y A218858 Cf. A225071, A225072 (number of terms at an odd distance from the origin).
%K A218858 nonn
%O A218858 0,3
%A A218858 _T. D. Noe_, Nov 12 2012