%I A117379
%S A117379 1,4,1,5,5,6,10,11,16,21,27,37,48,64,85,112,149,197,261,346,458,607,804,
%T A117379 1065,1411,1869,2476,3280,4345,5756,7625,10101,13381,17726,23482,31107,
%U A117379 41208
%V A117379 1,-4,1,-5,5,-6,10,-11,16,-21,27,-37,48,-64,85,-112,149,-197,261,-346,
               458,-607,804,
%W A117379 -1065,1411,-1869,2476,-3280,4345,-5756,7625,-10101,13381,-17726,23482,
               -31107,41208
%N A117379 Expansion of (1-4x)/(1-x^2+x^3).
%C A117379 Diagonal sums of number triangle A117377.
%F A117379 a(n)=sum{k=0..floor(n/2), (-1)^n*(C(k,n-2k)+4*C(k, n-2k-1))}
%Y A117379 Sequence in context: A099310 A021880 A075013 this_sequence A007309 A084890 
               A058662
%Y A117379 Adjacent sequences: A117376 A117377 A117378 this_sequence A117380 A117381 
               A117382
%K A117379 easy,sign
%O A117379 0,2
%A A117379 Paul Barry (pbarry(AT)wit.ie), Mar 10 2006