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 A098528 Expansion of (1+2x^3)/(1-x-2x^7). 0

%I

%S 1,1,1,3,3,3,3,7,11,15,27,39,51,63,91,135,195,303,459,663,915,1279,

%T 1819,2599,3811,5647,8299,11959,17075,24351,34747,49991,72579,105775,

%U 153611,221911,319315,458303,658267,948583,1371683,1986127,2873771,4151031

%N Expansion of (1+2x^3)/(1-x-2x^7).

%C The expansion of (1+kx^2)/(1-x-k^2*x^7) satisfies the recurrence a(n)=a(n-1)+k^2*a(n-7),a(0)=1,a(1)=1,a(2)=1,a(3)=k+1,a(4)=k+1, a(5)=k+1,a(6)=k+1 with a(n)=sum{k=0..floor(n/3), binomial(n-3k,floor(k/2))r^k}.

%F a(n)=a(n-1)+4a(n-7); a(n)=sum{k=0..floor(n/3), binomial(n-3k, floor(k/2))2^k}.

%Y Cf. A098524.

%K easy,nonn

%O 0,4

%A _Paul Barry_, Sep 12 2004

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