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 A186903 #8 Jul 16 2017 20:59:01
%S A186903 1,2,5,14,36,112,354,1193,4099,14374,51265,185143,675016,2481768,
%T A186903 9183221,34179072,127826852
%N A186903 Number of Gaussian primes (in the first half quadrant; i.e., 0 to 45 degrees) with real part <= 2^n.
%t A186903 c = 1; lst = {}; Do[ Do[ If[ PrimeQ[j + k*I, GaussianIntegers -> True], c++], {j, 2^(n - 1) + 1, 2^n}, {k, 0, j}]; AppendTo[lst, c]; Print@ c, {n, 16}]
%Y A186903 Cf. A055683.
%K A186903 nonn
%O A186903 0,2
%A A186903 _Robert G. Wilson v_, Mar 02 2011