%I A117372
%S A117372 1,3,1,0,4,1,0,3,5,1,0,0,7,6,1,0,0,3,12,7,1,0,0,0,10,18,8,1,0,0,0,3,22,
%T A117372 25,9,1,0,0,0,0,13,40,33,10,1,0,0,0,0,3,35,65,42,11,1,0,0,0,0,0,16,75,
%U A117372 98,52,12,1
%V A117372 1,-3,1,0,-4,1,0,3,-5,1,0,0,7,-6,1,0,0,-3,12,-7,1,0,0,0,-10,18,-8,1,0,
               0,0,3,-22,25,-9,
%W A117372 1,0,0,0,0,13,-40,33,-10,1,0,0,0,0,-3,35,-65,42,-11,1,0,0,0,0,0,-16,75,
               -98,52,-12,1
%N A117372 Riordan array (1-3x,x(1-x)).
%C A117372 Row sums are A117373. Diagonal sums are A117374. Inverse is A117375.
%F A117372 Number triangle T(n,k)=(-1)^(n-k)(C(k,n-k)+3*C(k, n-k-1))
%e A117372 Triangle begins
%e A117372 1,
%e A117372 -3, 1,
%e A117372 0, -4, 1,
%e A117372 0, 3, -5, 1,
%e A117372 0, 0, 7, -6, 1,
%e A117372 0, 0, -3, 12, -7, 1,
%e A117372 0, 0, 0, -10, 18, -8, 1,
%e A117372 0, 0, 0, 3, -22, 25, -9, 1
%Y A117372 Sequence in context: A166407 A159059 A127569 this_sequence A127570 A045406 
               A143468
%Y A117372 Adjacent sequences: A117369 A117370 A117371 this_sequence A117373 A117374 
               A117375
%K A117372 easy,sign,tabl
%O A117372 0,2
%A A117372 Paul Barry (pbarry(AT)wit.ie), Mar 10 2006