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Search: id:A098528
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| A098528 |
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Expansion of (1+2x^3)/(1-x-2x^7). |
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+0
1
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| 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; listen)
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OFFSET
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0,4
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COMMENT
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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}.
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FORMULA
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a(n)=a(n-1)+4a(n-7); a(n)=sum{k=0..floor(n/3), binomial(n-3k, floor(k/2))2^k}.
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CROSSREFS
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Cf. A098524.
Sequence in context: A092323 A092531 A125002 this_sequence A078229 A007428 A074816
Adjacent sequences: A098525 A098526 A098527 this_sequence A098529 A098530 A098531
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KEYWORD
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easy,nonn
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AUTHOR
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Paul Barry (pbarry(AT)wit.ie), Sep 12 2004
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