%I A084610
%S A084610 1,1,1,1,1,2,1,2,1,1,3,0,5,0,3,1,1,4,2,8,5,8,2,4,1,1,5,5,10,15,11,15,10,
               5,
%T A084610 5,1,1,6,9,10,30,6,41,6,30,10,9,6,1,1,7,14,7,49,14,77,29,77,14,49,7,14,
               7,
%U A084610 1,1,8,20,0,70,56,112,120,125,120,112,56,70,0,20,8,1,1,9,27,12,90,126,
               126,288
%V A084610 1,1,1,-1,1,2,-1,-2,1,1,3,0,-5,0,3,-1,1,4,2,-8,-5,8,2,-4,1,1,5,5,-10,-15,
               11,15,-10,-5,
%W A084610 5,-1,1,6,9,-10,-30,6,41,-6,-30,10,9,-6,1,1,7,14,-7,-49,-14,77,29,-77,
               -14,49,-7,-14,7,
%X A084610 -1,1,8,20,0,-70,-56,112,120,-125,-120,112,56,-70,0,20,-8,1,1,9,27,12,
               -90,-126,126,288
%N A084610 Triangle, read by rows, where the n-th row lists the (2n+1) coefficients 
               of (1+x-x^2)^n.
%e A084610 Rows:
%e A084610 {1},
%e A084610 {1,1,-1},
%e A084610 {1,2,-1,-2,1},
%e A084610 {1,3,0,-5,0,3,-1},
%e A084610 {1,4,2,-8,-5,8,2,-4,1},
%e A084610 {1,5,5,-10,-15,11,15,-10,-5,5,-1},
%e A084610 {1,6,9,-10,-30,6,41,-6,-30,10,9,-6,1},
%e A084610 {1,7,14,-7,-49,-14,77,29,-77,-14,49,-7,-14,7,-1},
%o A084610 (PARI) for(n=0,12, for(k=0,2*n,t=polcoeff((1+x-x^2)^n,k,x); print1(t",
               ")); print(" "))
%Y A084610 Cf. A002426, A084600-A084609, A084611-A084615.
%Y A084610 Sequence in context: A090001 A117166 A078996 this_sequence A129479 A075104 
               A008289
%Y A084610 Adjacent sequences: A084607 A084608 A084609 this_sequence A084611 A084612 
               A084613
%K A084610 sign,tabl
%O A084610 0,6
%A A084610 Paul D. Hanna (pauldhanna(AT)juno.com), Jun 01 2003