%I A117450
%S A117450 1,1,2,3,4,7,9,12,15,18,23,27,32,37,42,49,55,62,69,76,85,93,102,111,120,
%T A117450 131,141,152,163,174,187,199,212,225,238,253,267,282,297,312,329,345,
%U A117450 362,379,396,415,433,452,471,490,511
%N A117450 Expansion of (1-x+x^2+x^5)/((1-x)^2*(1-x^5)).
%C A117450 First differences are A117451. Second differences are A117452.
%F A117450 a(n)=2a(n-1)-a(n-2)+a(n-5)-2a(n-6)+a(n-7); a(n)=sum{k=0..n, C(n-k,L(k/
               5))}, where L(j/p) is the Legendre symbol of j and p; a(n)=(1/10-sqrt(5)/
               50)*cos(4*pi*n/5+2*pi/5)+sqrt(1/10+sqrt(5)/50)*sin(4*pi*n/5+2*pi/
               5) -(1/10+sqrt(5)/50)*cos(2*pi*n/5+pi/5)+sqrt(1/10-sqrt(5)/50)*sin(2*pi*n/
               5+pi/5) +(n^2+n+3)/5.
%Y A117450 Sequence in context: A038197 A023546 A084913 this_sequence A132381 A073152 
               A051061
%Y A117450 Adjacent sequences: A117447 A117448 A117449 this_sequence A117451 A117452 
               A117453
%K A117450 easy,nonn
%O A117450 0,3
%A A117450 Paul Barry (pbarry(AT)wit.ie), Mar 16 2006