%I A105667
%S A105667 1,2,4216,44834576
%N A105667 1/(2k)-th of area of primitive Pythagorean triangle with hypotenuse 5^(2^n), 
               where k is the product of all Mersenne primes not exceeding 2^(n+2) 
               - 1.
%H A105667 F. Barnes, <a href="http://www.geocities.com/fredlb37/node6.html">Divisors 
               of primitive Pythagorean triangles when the hypotenuse is to a power</
               a>
%Y A105667 Cf. A066770; A066771; A098918.
%Y A105667 Sequence in context: A048831 A135959 A114722 this_sequence A067668 A153737 
               A078933
%Y A105667 Adjacent sequences: A105664 A105665 A105666 this_sequence A105668 A105669 
               A105670
%K A105667 more,nonn
%O A105667 0,2
%A A105667 Lekraj Beedassy (blekraj(AT)yahoo.com), May 04 2005