%I #12 Jul 09 2016 13:30:13
%S 1,2,2,1,2,0,0,0,2,1,2,2,1,2,0,0,0,0,0,0,0,0,0,0,0,0,2,1,2,2,1,2,0,0,
%T 0,2,1,2,2,1,2,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
%U 0,0,0,0,0,0,0,0,0,0,0,0,2,1,2,2,1,2,0,0,0,2,1,2,2,1,2,0,0,0,0,0,0,0,0,0,0
%N An example of a d-perfect sequence.
%H D. Kohel, S. Ling and C. Xing, <a href="http://www.maths.usyd.edu.au/u/kohel/doc/perfect.ps">Explicit Sequence Expansions</a>, in Sequences and their Applications, C. Ding, T. Helleseth, and H. Niederreiter, eds., Proceedings of SETA'98 (Singapore, 1998), 308-317, 1999.
%F a(n) = ((-1)^(n+1)*A000108(n-1)) mod 3 - _Christian G. Bower_, Jun 12 2005
%o (PARI) C(n) = binomial(2*n, n)/(n+1);
%o a(n) = ((-1)^(n+1)*C(n-1)) % 3; \\ _Michel Marcus_, Jul 09 2016
%Y Cf. A000108.
%K nonn
%O 1,2
%A _N. J. A. Sloane_.
%E More terms from _Christian G. Bower_, Jun 12 2005