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 A068146 #14 Dec 05 2013 19:55:10
%S A068146 3,23,229,3121,776887,16774091,275311670611,302875106545597,
%T A068146 437893890380859119,808793517812627212561,827240252970236315921,
%U A068146 1978419655651397488675723,20880467999847900922348207352551
%N A068146 Primes of the form a^a - b^b.
%H A068146 Charles R Greathouse IV, <a href="/A068146/b068146.txt">Table of n, a(n) for n = 1..76</a>
%F A068146 The sum of the reciprocals converges to 0.38150016336280165719931278557192073226416041392427864458688292865... - _Cino Hilliard_, Dec 15 2002
%e A068146 229 = 4^4 - 3^3 is a prime.
%t A068146 Select[ Union[ Flatten[ Table[a^a - b^b, {a, 1, 40}, {b, 1, a - 1} ]]], PrimeQ ]
%o A068146 (PARI) v=[]; for(a=2, 400, forstep(b=a-1, 1, -2, if(ispseudoprime(t=a^a-b^b), v=concat(v,t)))); v \\ _Charles R Greathouse IV_, Feb 14 2011
%Y A068146 Cf. A068145.
%K A068146 nonn
%O A068146 1,1
%A A068146 _Amarnath Murthy_, Feb 23 2002
%E A068146 Edited and extended by _Robert G. Wilson v_ and _Sascha Kurz_, Mar 01 2002