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 A111745 #11 Nov 21 2013 12:48:45
%S A111745 3,5,7,13,11,17,19,29,23,37,31,41,43,53,47,61,59,73,67,89,71,97,79,
%T A111745 101,83,109,103,113,107,137,127,149,131,157,139,173,151,181,163,193,
%U A111745 167,197,179,229,191,233,199,241,211,257,223,269,227,277,239,281,251,293,263
%N A111745 a(2k-1) = k-th prime congruent to 3 mod 4, a(2k) = k-th prime congruent to 1 mod 4.
%C A111745 The graph shows the "race" between the two types of primes. - _T. D. Noe_, Nov 15 2006
%H A111745 Harvey P. Dale, <a href="/A111745/b111745.txt">Table of n, a(n) for n = 1..1000</a>
%F A111745 a(n)=A108546(n+1). [From _R. J. Mathar_, Aug 15 2008]
%t A111745 Module[{prs=Prime[Range[70]],m3,m1,min},m3=Select[prs,Mod[#,4]==3&];m1=Select[prs,Mod[#,4]==1&];min=Min[Length[m1],Length[m3]];Riffle[ Take[m3,min],Take[m1,min]]] (* _Harvey P. Dale_, Apr 15 2012 *)
%Y A111745 Cf. bisections A002144, A002145.
%K A111745 nonn
%O A111745 1,1
%A A111745 _Jon Perry_, Nov 19 2005
%E A111745 Edited, corrected and extended by _Franklin T. Adams-Watters_, Jul 19 2006
%E A111745 Corrected by _T. D. Noe_, Nov 15 2006