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%I #3 Oct 12 2012 14:40:25
%S 1,-1,1,15,113,783,5361,36879,255985,1794063,12689393,90505231,
%T 650379249,4705157135,34244198385,250572963855,1842382110705,
%U 13605619630095,100872203796465,750556607938575,5602962592235505,41952165966643215,314983352736153585
%N A sequence related to Catalan numbers A000108.
%C See also A115150, the third diagonal of triangle A113647 (called Y(2,1)).
%F (1-4*x)*(2*c(2*x)-1)/(1+x) with c(x) g.f. of A000108 (Catalan).
%F a(n)= A113647(n, n-1), n>=2.
%F a(n)= b(n)-4*b(n-1) with b(n):=A062992(n), n>=2; a(0)=1, a(1)=-1.
%e 15= a(3) = A062992(3) - 4*A062992(2) = 67 - 4*13.
%K sign,easy
%O 0,4
%A _Wolfdieter Lang_, Jan 13 2006