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 A162408 #3 Mar 31 2012 12:38:25 %S A162408 2,3,4,5,7,8,11,13,15,17,19,23,26,30,42,47,53,65,73,77,84,92,100,101, %T A162408 106,110,116,120,122,122,124,133,137,163,167,173,173 %N A162408 Solutions x to the equation x^x-y^y = some prime number for any y. %C A162408 These are the numbers a in the definition of A068146. %C A162408 If there are two solutions, like with (x,y) = (17,12) and (x,y) = (17,16) with %C A162408 the same x, only one instance of x is placed into the sequence, so there is no %C A162408 1-to-1 correspondence with terms in A068146. %C A162408 The corresponding set of y contains at least the numbers 1 to 6, 10, 12, 14, 16, 17, 19, 20, 22 etc %e A162408 Triples (x,y,prime) are (2,1,3), (3,2,23), (4,3,229), (5,2,3121), (7,6,776887), %e A162408 (8,5,16774091), (11,10,275311670611), (13,6,302875106545597), (15,4,437893890380859119), %e A162408 (17,12,827240252970236315921), (17,16,808793517812627212561) etc %t A162408 f[a_,b_]:=a^a-b^b; lst={};Do[Do[If[a>b,p=f[a,b]];If[PrimeQ[p],AppendTo[lst, a]],{b,4*4!}],{a,5*4!}];Union[lst] %Y A162408 Cf. A068146 %K A162408 nonn %O A162408 1,1 %A A162408 _Vladimir Joseph Stephan Orlovsky_, Jul 02 2009 %E A162408 Edited and extended by _R. J. Mathar_, Sep 16 2009