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A098528 Expansion of (1+2x^3)/(1-x-2x^7). 0
1, 1, 1, 3, 3, 3, 3, 7, 11, 15, 27, 39, 51, 63, 91, 135, 195, 303, 459, 663, 915, 1279, 1819, 2599, 3811, 5647, 8299, 11959, 17075, 24351, 34747, 49991, 72579, 105775, 153611, 221911, 319315, 458303, 658267, 948583, 1371683, 1986127, 2873771, 4151031 (list; graph; refs; listen; history; internal format)
OFFSET

0,4

COMMENTS

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}.

FORMULA

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

CROSSREFS

Cf. A098524.

Sequence in context: A092323 A092531 A125002 * A078229 A007428 A184099

Adjacent sequences:  A098525 A098526 A098527 * A098529 A098530 A098531

KEYWORD

easy,nonn

AUTHOR

Paul Barry (pbarry(AT)wit.ie), Sep 12 2004

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Last modified February 17 16:49 EST 2012. Contains 206058 sequences.