%I A046080
%S A046080 0,0,0,0,1,0,0,0,0,1,0,0,1,0,1,0,1,0,0,1,0,0,0,0,2,1,0,0,1,1,0,0,0,
%T A046080 1,1,0,1,0,1,1,1,0,0,0,1,0,0,0,0,2,1,1,1,0,1,0,0,1,0,1,1,0,0,0,4,0,
%U A046080 0,1,0,1,0,0,1,1,2,0,0,1,0,1,0,1,0,0,4,0,1,0,1,1,1,0,0,0,1,0,1,0,0
%N A046080 a(n) = number of integer sided right triangles with hypotenuse n.
%C A046080 a(n)=0 for n in A004144. - Lekraj Beedassy (blekraj(AT)yahoo.com), May 
               14 2004
%D A046080 A. H. Beiler, Recreations in the Theory of Numbers, New York: Dover, 
               pp. 116-117, 1966.
%H A046080 Ron Knott, <a href="http://www.mcs.surrey.ac.uk/Personal/R.Knott/Pythag/
               pythag.html">Pythagorean Triples and Online Calculators</a>
%H A046080 Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/
               PythagoreanTriple.html">Link to a section of The World of Mathematics.</
               a>
%H A046080 F. Richman, <a href="http://www.math.fau.edu/Richman/mla/pythag3s.htm">
               Pythagorean Triples</a>
%F A046080 Let n = 2^e_2 * product_i p_i^f_i * product_j q_j^g_j where p_i == 1 
               mod 4, q_j == 3 mod 4; then a(n) = (1/2)*(product_i (2*f_i + 1) - 
               1). - Beiler, corrected
%F A046080 8*a(n) + 4 = A046109(n) for n > 0. - Ralf Stephan, Mar 14 2004
%Y A046080 First differs from A083025 at n=65.
%Y A046080 Cf. A046079, A046081, A046082, A024362.
%Y A046080 Cf. A009000.
%Y A046080 Sequence in context: A015964 A088950 A083025 this_sequence A035227 A049340 
               A056929
%Y A046080 Adjacent sequences: A046077 A046078 A046079 this_sequence A046081 A046082 
               A046083
%K A046080 nonn
%O A046080 1,25
%A A046080 Eric Weisstein (eric(AT)weisstein.com)