%I A005313 M2573
%S A005313 1,3,6,13,29,70,175,449,1164,3035,7931,20748,54301,142143,372114,974185,
%T A005313 2550425,6677074,17480779,45765245,119814936,313679543,821223671,2149991448
%N A005313 Triangular anti-Hadamard matrices of order n.
%D A005313 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, 
               Academic Press, 1995 (includes this sequence).
%D A005313 S. Plouffe, Approximations de S\'{e}ries G\'{e}n\'{e}ratrices et Quelques 
               Conjectures, Dissertation, Universit\'{e} du Qu\'{e}bec \`{a} Montr\'{e}al, 
               1992.
%D A005313 R. L. Graham and N. J. A. Sloane, Anti-Hadamard matrices, Linear Alg. 
               Applic., 62 (1984), 113-137.
%H A005313 S. Plouffe, <a href="http://www.lacim.uqam.ca/%7Eplouffe/articles/MasterThesis.pdf">
               Approximations de S\'{e}ries G\'{e}n\'{e}ratrices et Quelques Conjectures</
               a>, Dissertation, Universit\'{e} du Qu\'{e}bec \`{a} Montr\'{e}al, 
               1992.
%H A005313 S. Plouffe, <a href="http://www.lacim.uqam.ca/%7Eplouffe/articles/FonctionsGeneratrices.pdf">
               1031 Generating Functions and Conjectures</a>, Universit\'{e} du 
               Qu\'{e}bec \`{a} Montr\'{e}al, 1992.
%F A005313 G.f.: [x(1-x-3x^2+x^3)]/[(1-3x+x^2)(1+x)(1-x)^2]. - Ralf Stephan, Apr 
               22 2004
%p A005313 A005313:=(1-z-3*z**2+z**3)/(z+1)/(z**2-3*z+1)/(z-1)**2; [Conjectured 
               by S. Plouffe in his 1992 dissertation.]
%Y A005313 a(n) = A064831(n-1) + n.
%Y A005313 Sequence in context: A078061 A018909 A093128 this_sequence A108639 A087218 
               A098075
%Y A005313 Adjacent sequences: A005310 A005311 A005312 this_sequence A005314 A005315 
               A005316
%K A005313 nonn
%O A005313 1,2
%A A005313 N. J. A. Sloane (njas(AT)research.att.com).