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 A133664 #15 Mar 31 2019 16:46:07
%S A133664 7,13,59,311,337,769,3137,3389,9631,46691,49783,49789,139969,143093,
%T A133664 823601,826673,826699,870253,916859,16777729,16780369,16780601,
%U A133664 16823903,16827001,17600761,17600813,18427427,33557561,33604213,34378231
%N A133664 Primes of the form a^a + b^b + c^c + d^d.
%H A133664 Charles R Greathouse IV, <a href="/A133664/b133664.txt">Table of n, a(n) for n = 1..10000</a>
%F A133664 A000040 INTERSECTION {A000312(a) + A000312(b) + A000312(c) + A000312(d)}.
%e A133664 a(1) = 7 = 2^2 + 1^1 + 1^1 + 1^1 = 4 + 1 + 1 + 1 = 7.
%e A133664 a(2) = 13 = 4 + 4 + 4 + 1.
%e A133664 a(3) = 59 = 27 + 27 + 4 + 1.
%e A133664 a(4) = 311 = 256 + 27 + 27 + 1.
%e A133664 a(5) = 337 = 256 + 27 + 27 + 27.
%e A133664 a(6) = 769 = 256 + 256 + 256 + 1.
%t A133664 Select[Union[ Flatten[Table[ a^a + b^b + c^c + d^d, {a, 1, 20}, {b, 1, a}, {c, 1, b}, {d, 1, c}]]], PrimeQ]
%o A133664 (PARI) v=[];for(a=1,100, for(b=1,a, for(c=1,b, for(d=1,c, if(ispseudoprime(t=a^a+b^b+c^c+d^d),v=concat(v,t)))))); v \\ _Charles R Greathouse IV_, Feb 15 2011
%Y A133664 Cf. A000040, A000312, A068145.
%K A133664 easy,nonn
%O A133664 1,1
%A A133664 _Jonathan Vos Post_, Dec 28 2007