%I A076980
%S A076980 8,17,32,54,57,100,145,177,320,368,512,593,945,1124,1649,2169,2530,4240,
%T A076980 5392,6250,7073,8361,16580,18785,20412,23401,32993,60049,65792,69632,
%U A076980 93312,94932,131361,178478,262468,268705,397585,423393,524649,533169
%N A076980 Leyland numbers: numbers expressible as n^k + k^n nontrivially, i.e. 
               n,k > 1 (to avoid n = (n-1)^1 +1^(n-1)).
%C A076980 Crandall & Pomerance named these numbers in honor of Paul Leyland, in 
               reference to 2638^4405 + 4405^2638, the largest known prime of this 
               form. - Alonso Delarte (alonso.delarte(AT)gmail.com), Apr 05 2006
%D A076980 R. Crandall and C. Pomerance, Prime Numbers: A Computational Perspective, 
               Springer, NY, 2005
%H A076980 Wikipedia, <a href="http://en.wikipedia.org/wiki/Leyland_number">Leyland 
               number</a>.
%e A076980 a(7) = 177 because we can write 177 = 2^7 + 7^2
%t A076980 Take[Sort[Flatten[Table[x^y + y^x, {x, 2, 100}, {y, x, 100}]]], 42] - 
               Alonso Delarte (alonso.delarte(AT)gmail.com), Apr 05 2006
%Y A076980 Prime subset of this sequence, A094133.
%Y A076980 Sequence in context: A077222 A077221 A106648 this_sequence A159696 A049713 
               A041849
%Y A076980 Adjacent sequences: A076977 A076978 A076979 this_sequence A076981 A076982 
               A076983
%K A076980 nonn
%O A076980 1,1
%A A076980 Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Oct 23 2002
%E A076980 More terms from Benoit Cloitre (benoit7848c(AT)orange.fr), Oct 24 2002
%E A076980 More terms from Alonso Delarte (alonso.delarte(AT)gmail.com), Apr 05 
               2006